DATA RELEASE HIGHLIGHTS – JUNE 2018

Following today’s data release, the DMDD website now contains detailed phenotype data for nearly 700 embryos from 82 different knockout mouse lines. Highlights include the identification of limb defects and cysts in Col4a2 knockouts and replication of the major features of Meckel syndrome in B9d2 knockouts.

We have begun to add immunohistochemistry image data for the brain and spinal cord of some embryos at E18.5. These images give further information about lines in which the embryos appeared morphologically normal at E14.5, but were still not viable. We have also added viability data for every line at both E9.5 and E14.5.

Together with the placental phenotype data that we hold for more than 100 knockout lines, the DMDD website is a rich resource for those investigating the effect of gene mutations on embryo development, and may provide clues about the genetic basis of rare diseases.


LIMB DEFECTS SEEN IN Col4a2 KNOCKOUTS

In humans, COL4A2 mutations have been linked to porencephaly, a rare disorder with phenotypes that include the development of intracranial cysts. In the latest DMDD data, Col4a2 knockouts have a variety of nervous system disorders in line with porencephaly. However, all four embryos also show abnormal autopod morphology and cysts between the nasal septum and the oral cavity, as well as other morphological defects.

 

A Col4a2 knockout embryo has a cyst between the nasal septum and oral cavity (left) and abnormal autopod morphology (right). The individual fingers don’t diverge distally and can’t be discerned from an external view.

 


B9d2 KNOCKOUTS MODEL MECKEL SYNDROME

In humans, mutations of the gene B9D2 have been linked to Meckel syndrome, a severe disorder caused by dysfunction of the primary cilia during the early stages of embryogenesis. Meckel syndrome is characterised by multiple kidney cysts, occipital encephalocele (where a portion of the brain protrudes through an opening in the skull) and polydactyly, but it also commonly affects the brain and spinal cord, eyes, heart, lungs and bones.

B9d2 knockout mouse embryos included in our latest data release show the major features of Meckel syndrome, including polydactyly and defects in the brain, peripheral nervous system, heart and vascular system. They also display situs defects, where the left-right asymmetry of the body did not develop as expected. The image below shows a B9d2 knockout embryo with left pulmonary isomerism and symmetric branching of the principle bronchi from the trachea.

 

A B9d2 embryo showing situs defects (left). A magnified view (right) shows that both lungs have developed with a single-lobe structure. In mice the left lung usually has one lobe, while the right lung has four. In addition, the principle bronchi (red arrows) have branched symmetrically from the trachea. This branching would normally have a distinct asymmetry.

 


NEURAL IMAGE DATA NOW AVAILABLE

In around 20% of embryonic lethal lines, embryos appear morphologically normal at E14.5 but still go on to die before or shortly after birth. To understand more about why these embryos were not viable, DMDD colleagues Professor Corinne Houart and Dr Ihssane Bouybayoune at Kings College London analysed the lines at E18.5 – when embryo development is almost complete. They used immunohistochemistry to identify abnormalities in the brain and spinal cord that could not be picked up in our standard, whole-embryo morphological analyses. This data is now available for the line Trappc9, and additional lines will be added in future data releases.

 

Click to view larger image.
Immunohistochemistry analysis of the brains of two Trappc9 knockout mice. The calretinin (green) + neurofilament (red) combined stain highlights interneurons and axons, while Hoechst (blue) is a nuclear stain.

 

Neural images are available as 20-micron sections through the brain and spinal cord, and the images from different embryos can be compared side by side using the stack viewer. A separate Nissl stain was used to highlight neural death and these images can also be explored online.


 

A FULL LIST OF NEW DATA IN THE LATEST RELEASE

LATEST DATA RELEASE HIGHLIGHTS INCLUDING NEW HEART DEFECT ASSOCIATIONS

Our latest data release includes HREM image data for an additional 5 lines, and HREM phenotyping data for 4 lines. Five additional early lethal lines have also been identified, as well as placental phenotype data for more than 100 mutant lines, with associated placenta morphology and yolk sac images.

Throughout the DMDD project we continue to add data for existing lines, and in this release we have added P14 viability for mutant lines, Theiler stage (where assessed), and the voxel size of each HREM image stack.

Initial analysis of the new HREM phenotyping data shows two lines newly associated with heart defects.


Oaz1 ASSOCIATED WITH DORV

Oaz1 is a gene regulating levels of polyamines within the cell and is widely distributed in cells and tissues of the body. Our data now shows that removal of this gene causes a serious abnormality in heart development in which the vessel normally carrying blood from the left ventricle of the heart (the aorta) is in fact attached to the right ventricle (a defect known as “double outlet right ventricle” or DORV). As with many mutant lines, the embryos also show extensive swelling of the body (“edema”).

Left panel: a view of the heart seen from the right side and showing both the pulmonary trunk (red arrow) and the aorta (yellow arrow) drain from the right ventricle. Right panel: a cross section through the body at the level of the heart shows the extent of swelling (arrows) in tissue beneath the skin.

 


Cc2d2a ASSOCIATED WITH VSD AND OSTIUM PRIMUM DEFECT

Cc2d2a encodes a protein that plays a critical role in formation of cell cilia and mutations in this gene are associated with diseases such as Meckel syndrome type 6, which results in a broad range of symptoms such as polydactyly, cleft palate and kidney malformations. Our data reveals that removal of the Cc2d2a gene also has profound effects on heart development. Not only do the embryo hearts fail to complete separation of the left and right ventricular chambers (a “ventricular septal defect”), they also fail to form a proper wall between the left and right atrial chambers (an “ostium primum defect”). In addition, they have lost a swath of tissue at the junction between the atria and ventricles (the “vestibular spine”) that is essential for completing chamber separation.

Shows three views of the embryo heart. The lefthand panel shows the ventricular septal defect; the middle panel shows the osmium primum defect and the right panel shows the absence of vestibular spine tissue which normally enables the atrial and ventricular septal walls to attach to each other.

Many of the genes studied by DMDD do not currently appear to be associated with any disease, however careful analysis of the phenotypes from lines such as these could contribute to the identification of new disease models, and our data is freely available at dmdd.org.uk in order to encourage this. For more information please email contact@dmdd.org.uk.


A FULL LIST OF NEW DATA IN THE LATEST RELEASE

9.5 MILLION EMBRYO IMAGES NOW AVAILABLE

A new set of DMDD embryo and placenta data has been released today, taking our total dataset to 9.5 million images of around 1300 embryos. Phenotypes are available for embryos from 73 different knockout lines, and we have phenotyped the placentas from 124 lines. We have also added data on the sex of each embryo.

Visitors to our website can now compare HREM embryo images with the closest-matching, annotated histological section from the Kaufman Atlas of Mouse Development. This follows a major project by the eMouseAtlas team at the University of Edinburgh to digitise the Kaufman Atlas at high resolution. The annotated Kaufman sections can be viewed alongside DMDD embryo images to help users who are unfamiliar with the detailed morphological features of a mouse embryo as it develops.

All DMDD data can be freely accessed at dmdd.org.uk, or you can continue reading for highlights from the latest lines to be made publicly available.


SEVERE BRAIN PHENOTYPES

Phenotyping of Hmgxb3 knockout embryos revealed severe brain defects, with half of the embryos displaying exencephaly. Embryos from this line also had a range of phenotypes including edema, abnormalities of the optic cup, and defects of the venous system including an abnormal ductus venosus valve and blood in the lymph vessels.

 

Click to view larger image.
An Hmgxb3 homozygous knockout embryo displays exencephaly.

 


 

POTENTIAL MODELS OF HUMAN DISEASE

A number of genes studied by DMDD have already been associated with human diseases. For example, Prmt7 mutations have been associated with Short Stature Brachydactyly Obesity Global Developmental Delay Syndrome, an autosomal recessive disease characterised by developmental delay, learning disabilities, mild mental retardation, delayed speech, and skeletal abnormalities. Strikingly, in the Prmt7 knockout embryos studied, the most common phenotypes included neuroma of the motoric part of the trigeminal nerve (a tumour within the skull, affecting the nerve controlling the jaw movements needed for speaking and chewing) and abnormalities of the hypoglossal nerve (which controls movement of the tongue) and the ribs.

Image data has been added for both Cc2d2a and Xpnpep1 knockouts. Mutations of the Cc2d2a gene are known to cause Meckel and Joubert syndromes, while Xpnpep1 has been associated with billiary atresia.

Many of the genes studied by DMDD do not currently appear to be associated with any disease, for example Hmgxb3 or Cbx6. There is potential that careful analysis of the phenotypes from lines such as these could contribute to the identification of new disease models, and our data is freely available in order to encourage this.


A DETAILED DESCRIPTION OF NORMAL MOUSE EMBRYO DEVELOPMENT

The Atlas of Mouse Development by Professor Matthew Kaufman describes normal mouse embryo anatomy using a series of hundreds of annotated histological sections. Even today, twenty three years after its publication, it is still considered to be the gold standard for describing mouse embryo development. As part of a project to update the book in 2012, the original sections were digitised by the Edinburgh Mouse Atlas Group and made freely available on their eHistology resource.

The images have now been integrated into the DMDD database, and users can directly compare any HREM embryo image with the closest-matching annotated Kaufman section.

 

Click to view larger image.
Each HREM embryo image can now be viewed alongside the closest-matching section from the Kaufman Atlas of Mouse Development.

 

This new feature is intended to help users who are not fully confident of the details of mouse developmental anatomy. It means that mutant mouse data can now be explored alongside a fully-annotated wild-type reference point.


A FULL LIST OF NEW DATA

Embryo phenotype data added for: Hmgxb3 and Prmt7

Embryo image data added for: Cbx6, Cc2d2aHmgxb3, Prmt7 and Xpnpep1

Placenta images and phenotypes added for: Mir96

To explore the data, visit dmdd.org.uk or for more information please email contact@dmdd.org.uk.

NEW PHENOTYPE DATA FOR EMBRYOS AND PLACENTAS

Today, DMDD has released many new images and phenotypes for embryos and placentas from embryonic lethal knockout mouse lines. We now hold data on 70 mutant lines that have been phenotyped in detail using the Mammalian Phenotype ontology. The resulting data is freely available to the scientific community and is a potential goldmine of information about the genetic basis of developmental disorders.

The new data is accompanied by several exciting updates to our website. These include the ability to search for phenotypes by anatomy terms and the release of additional data about gene knockouts that are lethal very early in embryonic development. Highlights of the release, including examples of interesting phenotypes, can be found below.

 

SEARCH FOR PHENOTYPES USING ANATOMY TERMS

Following a major update to our search tool, users of the DMDD database can now search for phenotypes by anatomy term. This new functionality is designed to help researchers of specific organ or tissue types to quickly identify all phenotypes that are relevant to their studies. Choose from embryo and adult anatomy terms for both humans and mice.

 

Image of the DMDD search box
New search functunality gives users the option to search for phenotypes by anatomy term.

 

FIND GENE KNOCKOUTS THAT ARE LETHAL BEFORE E9.5

Around a third of the knockout lines studied by the DMDD programme have been found to cause lethality before 9.5 days of gestation. Although it is not possible for us to image and phenotype embryos from these lines, we have added them to our database and they can be found using the ‘search’ tool.

For a full list of lines that are lethal before E9.5, visit our Early lethals page.

 

EXPLORE THE NEW EMBRYO PHENOTYPE DATA

In our latest release we’ve made phenotypes available for 7 new knockout lines. These include Cfap53, which is known to be involved in left-right asymmetric patterning in humans. In mouse embryos we identified the phenotype ‘abdominal situs ambiguus’, in which the abdominal organs have neither the usual nor the mirror-image arrangement.

We have also released data on Fut8. This gene is linked to Leukocyte Adhesion Deficiency, a syndrome with symptoms including microcephaly and abnormality of the tongue and palate. In the mouse we identified various phenotypes related to the hypoglossal nerve, which controls movements of the tongue.

Some further highlights from the phenotypes released today include spinal haemorrhage in a Fut8 knockout embryo, a perimembraneous ventricular septal defect in an Arid1b knockout embryo and abnormal lens epithelium morphology in an Actn4 knockout embryo.

 

Click to view larger image.
A Fut8 knockout embryo found to have a spinal haemorrhage.

 

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Abnormal lens epithelium morphology in an Actn4 embryo. Lens epithelial cells are the parental cells responsible for growth and development of the lens.

 

 

In total, 162 distinct phenotypes were identified across 91 new mutant and wild-type control embryos. Phenotype data for a total of 81 new placentas has also been released.

 

A FULL LIST OF THE NEW DATA

HREM embryo image stacks added for Dennd4c, Dnajc8 and Pigf.

Embryo phenotypes added for Actn4, Arid1b, Cfap53, Cyp11a1, Dmxl2, Fut8 and Mfsd7c.

Placenta images and phenotypes added for B9d2, Cbx6, Commd10, Coq4, Dcx, Dhx35, Fam160a1, Gpatch1, Mfsd7c, Oaz1 and Smg1.

 

All image and phenotype data from the DMDD programme can be accessed at dmdd.org.uk. For assistance, please email contact@dmdd.org.uk.

NEW DATA REVEALS HOW GENE KNOCKOUTS AFFECT WHOLE EMBRYO GENE EXPRESSION

New DMDD data released on Expression Atlas today reveals the effect of single gene knockouts on the expression of all other genes in the mouse genome. The gene expression profiles of 11 knockout lines have been derived from whole embryos harvested at E9.5, and the results can be compared with wild-type controls using an interactive online tool. Users can investigate which genes are differentially expressed as a result of a gene knockout, with the potential to uncover genes with similar roles or compensatory effects when a related gene is knocked out.

Data for additional lines will be released throughout 2017. The ultimate goal is to bring these molecular phenotypes together with the morphological phenotypes that have already been derived by the DMDD programme, to offer new insights about the effects of gene knockout on embryo development.


THE GENOMIC EFFECTS OF Ssr2 KNOCKOUT

The knockout of Ssr2 in the mouse was found to affect the expression level of 325 genes in total, and this is one of the 11 new datasets that can be explored in Expression Atlas.

The differential expression of each gene is described using the log2 fold change – a measure that describes the ratio of gene expression in the knockout to the level of gene expression in a wild-type control. A negative fold change (shown in blue in the image below) means that the gene was expressed at a lower level in the mutant. A positive fold change (shown in red in the image below) means that the gene was expressed at a higher level in the mutant.

 

A visualisation of the level of differential expression of 8 genes affected by the knockout of Ssr2.
Eight genes that are differentially expressed due to a knockout of the gene Ssr2 (above a cut off log2 fold change of 0.4). Six genes are expressed at a higher level, while Mfap2 and Ssr2 are expressed at a lower level.

 

The interactive tool in Expression Atlas allows different cut-offs to be applied to the fold change, so the genes displayed can be restricted to those with a large differential expression. The image above shows the 8 genes with a fold change greater than 0.4 as a result of knocking out the gene Ssr2.

The tool can also be used to visualise the data in graphical form. The plot below shows the fold change for each gene, allowing the user to quickly ascertain the extent to which a gene knockout caused differential expression of other genes. All 325 genes considered to have a significant change in the level of gene expression are plotted in red, with the rest shown in grey.

 

Graphical visualisation of the fold change for each gene in the mouse genome, following knockout of the Ssr2 gene.
A graphical visualisation of the fold change for each gene. The outlier with a fold change of -3.5 is the gene Ssr2, which has a much-reduced expression level in an Ssr2 knockout embryo.

 


The full list of lines with data currently available is: 1700007K13Rik, 4933434E20Rik, Adamts3, Anks6, Camsap3, Cnot4, Cyp11a1, Mir96, Otud7b, Pdzk1 and Ssr2.

The full dataset for any line can be downloaded for further analysis, while the individual line pages on Expression Atlas integrate the DMDD data with other pre-existing data, in cases where a gene has already been shown to alter expression.

NEW EMBRYO PHENOTYPE DATA AVAILABLE

New image and phenotype data for embryos and placentas from embryonic lethal knockout mouse lines has been made available on the DMDD website today. The knockout data includes the ciliary gene Rpgrip1l as well as Atg16l1, a gene encoding a protein that forms part of a larger complex needed for autophagy. In total we have added HREM image data for 10 new lines, embryo phenotypes for 11 lines and placenta image and phenotype data for 6 lines.

The new data was released at the same time as enhancements to our website, which have been described in a separate blog post. Keep reading to see some highlights from the phenotype data.


DETAILED EMBRYO PHENOTYPES REVEALED

The comprehensive and detailed nature of DMDD embryo phenotyping means that we are able to identify a wide range of abnormalities. In the data released today, a total of 423 phenotypes were scored across 78 embryos. These included gross morphological defects such as exencephaly and edema, but also abormalities on a much smaller scale such as an unusually small dorsal root ganglion, absent hypoglossal nerve and narrowing of the semicircular ear canal.

In the image below, a Trim45 embryo at E14.5, was found to have abnormal optic cup morphology and aphakia (a missing lens).

Click to view larger image.
HREM imaging of a Trim45 knockout embryo reveals abnormal optic cup morphology and aphakia on the left side.

3D modelling of the exterior of an Rpgrip1l knockout embryo at E14.5 revealed a cleft upper lip, as well as polydactyly.

Click to view larger image.
A 3D HREM model of an Rpgrip1l embryo shows a cleft upper lip.

All phenotypes are searchable on the DMDD website, highlighted on relevant images, and the full-resolution image data is available to explore online.


SYSTEMATIC PLACENTAL ANALYSIS

DMDD also carries out systematic phenotyping of the placentas from knockout lines. The image below shows a Cfap53 knockout placenta at E14.5, which was found to have an aberrant fibrotic lesion. The density of fetal blood vessels was also considerably reduced, the overall effect being to reduce the nutrient flow from mother to embryo.

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Placental histology for the line Cfap53 shows a fibrotic lesion (large arrow) and several regions of reduced blood vessel density (small arrows).

 


GENE EXPRESSION PROFILES

Work is underway to measure the gene expression profiles for embryos from embryonic lethal knockout lines, a study that complements the morphological phenotype data we are gathering. One of our ultimate goals is to allow data users to explore correlations between gene, morphological phenotype and gene expression profile. The first part of this dataset was released recently – a temporal baseline gene expression profile for wild type embryos.

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Example expression profiles of Nacad and Pdzk1 with increasing somite number. The data shows that, at this depth of sequencing, Nacad is switched on during somitogenesis and Pdzk1 is switched off.

 

The expression data is now accessible via a dedicated wild type gene expression profiling page on the DMDD website, which also gives background information about the analysis. Mutant expression data will follow in the new year.


LINKS BETWEEN DMDD GENES AND HUMAN DISEASE

Many of the genes studied by the DMDD programme are known to have links to human disease, including several new lines that have been made available in this release.

Rpgripl1: in humans, mutations in RPGRIPL1 are known to cause Joubert Syndrome (type 7) and Meckel Syndrome (type 5), a rare disorder affecting the cerebellum.

Cfap53: the human ortholog of this gene is known to be associated with visceral heterotaxy-6, in which organs have an abnormal placement and/or orientation.

Arhgef7: in humans the ortholog is associated with Borjeson-Forssman-Lehmann Syndrome.

Arid1b: in humans, mutations in ARID1B are associated with Coffin-Siris Syndrome.

Embryonic lethal lines with no known links to human disease may also be novel candidate genes for undiagnosed genetic disorders. Visit the DMDD website to explore the phenotype data.


A FULL LIST OF NEW DATA

HREM embryo image data has been added for Actn4, Arid1b, Cfap53, Crim1, Cyp11a1, Dmxl2, Fut8, Gas2l2, Mfsd7c, Rala.

Embryo phenotype data has been added for Atg16l1, Capza2, Coro1c, Crim1, Cyfip2Gas2l2, Gm5544Rala, Rpgrip1l, Syt1, Trim45.

Placenta image and phenotype data has been added for Arhgef7, Arid1b, Fam21, Fut8, Med23, Timmdc1.

If you have questions about the DMDD programme or our data, please email contact@dmdd.org.uk.

A NEW BASELINE RNA EXPRESSION PROFILE FOR MOUSE EMBRYOS

Knowing the ‘normal’ expression of genes during embryo development is key to understanding the differences that occur due to genetic mutations.

As part of work to understand the underlying transcriptional processes in developing embryos from knockout mouse lines, DMDD has now released a gene expression profile for wild-type mouse embryos between E8.5 and E10.5. The new dataset reveals the typical expression profile of genes during this crucial period of embryonic development, including their abundance, and when they are turned on and off.


NEW DATA AVAILABLE

RNA-seq has been used to establish the expression profile for whole, wild-type embryos at each somite number between 4 and 36 (excluding 29 – 33). This range corresponds roughly to the period E8.5 – E10.5, a vital period during which many organs and systems begin to develop.

The resulting data is now available in Expression Atlas. It’s a temporal baseline expression reference derived from wild-type embryos, which adds to EBI’s established resource to give a more complete picture of gene expression during embryonic development.


WHY DERIVE A BASELINE EXPRESSION PROFILE?

The wild-type baseline helps us to answer the question “what does ‘normal’ whole-embryo gene expression look like during development?” This is hugely important, as we can only really begin to explore what is abnormal once we know what is normal.

More specifically, the baseline highlights patterns in the way different genes are usually expressed as an embryo develops: when they are turned on and off; their abundance and whether their expression is covariant with other genes. Example expression profiles are shown below for Nacad and Pdzk1, indicating that at this depth of sequencing Nacad is switched on during somitogenesis and Pdzk1 is switched off.

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Expression profiles of the Nacad and Pdzk1 genes with increasing somite number. The white boxes indicate no expression at a cut off of 0.6 fpkm (fragments per kilobase per million). The numbers in the boxes give the level of expression in fpkm, with bluer boxes indicating a higher level of expression.

MOLECULAR PHENOTYPING

For DMDD, the new dataset will underpin work on molecular phenotyping, by allowing us to understand whether the expression patterns of mutant embryos are significantly different from the wild-type. The ultimate goal is to allow users to correlate a given gene with the physical manifestations of its knockout in the developing embryo, and the underlying transcriptional processes.

The relationship between gene, morphological phenotype and molecular phenotype in the DMDD programme.
The DMDD database will ultimately allow correlation between genes, morphological phenotypes and molecular phenotypes (based on transcriptional processes).

However the data is a valuable resource for any researcher interested in gene expression during embryonic development, and is free to use. You can explore the data further in Expression Atlas.

DATA RELEASE – AUGUST 2016

New embryonic-lethal knockout mouse lines are now available on the DMDD database.

If you haven’t previously taken a look at our data (or even if you have) now would be a good time to explore our website.  We’ve added new embryo phenotype data and HREM images for many knockout lines, taking our total dataset to more than 4 million images of 550 embryos. We also have placental histology images and phenotypes available for over 100 mutant lines.

This post explores some of the phenotypes observed in the new data, and highlights new lines that could be relevant for clinicians researching rare diseases and developmental disorders. But there isn’t enough space here to include every interesting feature of the data – the best thing to do is to explore it yourself.


EMBRYO PHENOTYPES

Our phenotypers at the Medical University of Vienna have observed many interesting phenotypes in the new data.

Embryos from the line Adamts3 display both subcutaneous edema and bifid ureter. A bifid ureter is the most common malformation of the urinary system, [1] in which there is a duplex kidney drain into separate ureters. This observation highlights the incredible resolution of HREM images, which allow detailed phenotypes to be scored for each embryo.

Click to view larger image.
Bifid ureter (left side) observed in an Adamts3 mutant embryo. The red arrows highlight a single ureter on the right side, but two branches on the left side.

 

Embryos from the line H13 suffered from severe abnormalities in heart morphology, and had an abnormal heart position within the body. The stomach situs was also inverted, as shown in the image below. Note that severely malformed embryos often have different tissue characteristics, which can result in reduced image clarity.

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Comparison between a H13 mutant embryo (left) and its wild-type litter-mate (right). The yellow arrows indicate situs invertus of the stomach.

 

Embryos from the line Brd2 exhibited a profound ventricular septal defect, as shown in the video below.

 


PLACENTAL PHENOTYPES

Our placental image and phenotype dataset is growing rapidly and now contains more than 100 lines.

H13 knockout placentas were smaller than their wild-type counterparts and showed reduced vascularisation in the placental labyrinth, the region of the placenta that allows nutrient and gas exchange between the mother and the developing embryo.

Click to view larger image.
A comparison of the placenta from a H13 mutant embryo and that of its wild-type litter-mate.

Vascularisation of the labyrinth is crucial to allow the embryo to receive the oxygen and nutrients needed for normal development. This is just one example, but many more placental phenotypes are available on our website.


LINKS TO CLINICAL STUDIES

Systematic knockout mouse screens can offer a wealth of information about the genetic basis of rare diseases. Many DMDD lines have human orthologues known to be associated with developmental disorders, and the nature of our study means that it would not be possible to derive equivalent systematic data from human patients.

New knockout lines of potential clinical interest include:

Brd2: the human ortholog of this gene is associated with epilepsy, generalised, with febrile seizures plus, type 5.

Cog6: in humans, COG6 is linked to Shaheen Syndrome and congenital disorder of glycosylation, type IiI.

Npat: the human ortholog is associated with Ataxia-telangiectasia, a rare inherited disorder affecting the nervous and immune systems.

Nsun2: in humans, NSUN2 is linked to mental retardation, autosomal recessive 5 and Dubowitz syndrome.


A FULL LIST OF NEW DATA

Embryo phenotype data added for: Adamts3, Brd2, Cog6, Cpt2, Dhx35, H13, Mir96, Npat, Nsun2, Pdzk1.

HREM embryo images added for: Atg16l1, Capza2, Cog6, Coro1c, Cyfip2, Dhx35, Gm5544, Nadk2, Nrbp1, Rab21, Rpgrip1l, Syt1.

Placenta image and phenotype data added for: 1110037F02Rik, Actn4, Atg16l1, Camsap3, Capza2, Cfap53, Coro1c, Crim1, Crls1, Cyfip2, Dmxl2, Gm5544, Gtpbp3, H13, Nsun2, Rab21, Rala, Rpgrip1l, Syt1, Trim45.


REFERENCES

[1] Obstructed bifid ureteric system causing unilateral hydronephrosis, A. Bhamani1 and M. Srivastava2, Rev Urol. 2013, 15(3) p.131–134, PMC3821993.

1 Department of General Medicine, The Ipswich Hospital, Ipswich, UK.
2 Department of Radiology, Barking, Havering and Redbridge NHS Trust, Romford, Essex, UK.

DATA RELEASE – MAY 2016

New DMDD data is now available on our website. This week we’ve added HREM embryo image stacks for 12 new lines, embryo phenotype data for 12 lines and placental phenotype data for a further 10 lines.

For full details on what we’ve released see the bottom of this post, or look at our updates page.  But here are a few highlights we found while reviewing the data.

 

EMBRYO PHENOTYPES

Our embryo phenotyping team were particularly interested in the lines Smg9 and Col4a3bp.

Smg9 showed malformations affecting several organ systems. The most prominent were malformations in the nervous system (including exencephaly) and in the cardiovacular system. This data release includes phenotype annotations for 6 embryos in the Smg9 line, meaning that penetrance data can be explored for the related phenotypes.

An embryo with a mutation of the gene Smg9 displays exencephaly.
An embryo with a mutation of the gene Smg9 displays exencephaly.

Line Col4a3bp showed malformations of the cardiovascular system and the axial skeleton.

 

PLACENTAL DATA

Our placenta team highlighted Brd2, a transcriptional regulator belonging to the therapeutically important BET (bromodomains and extra terminal domain) family of proteins with epigenetic functions.

As well as exhibiting severe growth retardation, placentas from this line showed a massively reduced vascular density that will result in insufficient nutrient supply to the embryo.

Brd2 placentas display reduced vascular density.
A comparison of wild-type and mutant placentas for the line Brd2 shows reduced vascular density in the mutant placentas.

 

The Brd2 line is also interesting from the point of view of mouse production. When the DMDD programme began back in 2013, all our knockout mouse lines were made using embryonic stem cells. Our partners at the Wellcome Trust Sanger Institute have recently begun using the CRISPR-Cas9 technique for creating knockout mice, and Brd2 is the first of these lines to make its way to the DMDD analysis pipeline.

 

CLINICAL INTEREST

Many of the genes studied by DMDD have human orthologues, mutations in which are related to known conditions. DMDD data is a way to examine, in great detail, the resulting phenotypes when these genes are knocked out in a mouse model.

New lines that may be relevant to clinicians (although not an exhaustive list) are:

Col4a3bp: in humans, diseases associated with COL4A3BP include mental retardation, autosomal dominant 34 and goodpasture syndrome.

Ssr2: the human ortholog of this gene is associated with calcaneonavicular coalition.

Trappc9: in humans, diseases associated with TRAPPC9 include intellectual disability, obesity, brain malformations, facial dysmorphism and Birk-Barel mental retardation dysmorphism syndrome.

 

A FULL LIST OF NEW DATA

HREM image data: Brd2, Camsap3, Col4a3bp, Cpt2, Eif3h, H13, Mir96, Npat, Nsun2, Pdzk1, Smg9, Trim45.

Embryo phenotype data: Adamts3, Camsap3, Col4a3bp, Dbn1, Duoxa2, Exoc3l2, Ogdh, Slc5a7, Smg9, Ssr2, Traf2, Trappc9.

Placental phenotype data: Brd2, Cnot4, Cog6, Col4a3bp, Cpt2, Cyp11a1, Pdzk1, Pgap2, Smg9, Wrap53.

Data is searchable by both gene and phenotype, and all image data can be viewed online at full resolution. To request the data offline, or for any enquiries please get in touch: contact@dmdd.org.uk.