The family of WD40-repeat (WDR) proteins is one of the largest in eukaryotes, but little is known about their function in brain development. Among 26 WDR genes assessed, we found 7 displaying a major impact in neuronal morphology when inactivated in mice. Remarkably, all seven genes showed corpus callosum defects, including thicker (Atg16l1, Coro1c, Dmxl2, and Herc1), thinner (Kif21b and Wdr89), or absent corpus callosum (Wdr47), revealing a common role for WDR genes in brain connectivity. We focused on the poorly studied WDR47 protein sharing structural homology with LIS1, which causes lissencephaly. In a dosage-dependent manner, mice lacking Wdr47 showed lethality, extensive fiber defects, microcephaly, thinner cortices, and sensory motor gating abnormalities. We showed that WDR47 shares functional characteristics with LIS1 and participates in key microtubule-mediated processes, including neural stem cell proliferation, radial migration, and growth cone dynamics. In absence of WDR47, the exhaustion of late cortical progenitors and the consequent decrease of neurogenesis together with the impaired survival of late-born neurons are likely yielding to the worsening of the microcephaly phenotype postnatally. Interestingly, the WDR47-specific C-terminal to LisH (CTLH) domain was associated with functions in autophagy described in mammals. Silencing WDR47 in hypothalamic GT1-7 neuronal cells and yeast models independently recapitulated these findings, showing conserved mechanisms. Finally, our data identified superior cervical ganglion-10 (SCG10) as an interacting partner of WDR47. Taken together, these results provide a starting point for studying the implications of WDR proteins in neuronal regulation of microtubules and autophagy.WD40-repeat proteins | corpus callosum agenesis | microcephaly | neurogenesis | autophagy T he function of WD40-repeat (WDR)-containing proteins, one of the largest eukaryotic protein families, is largely unknown. Their importance is, however, evident based on their highly conserved repeating units from bacteria to mammals (1), commonly made of seven repetitive blades of 40 amino acids that end with a tryptophan-aspartic acid dipeptide at the C terminus.As shown by crystallography studies, including the crystal structure of the beta gamma dimer of the G-protein transducin (2), a classical WDR protein, all WDR proteins are predicted to fold into a circularized beta-propeller structure, serving as a rigid platform (or scaffold) for protein-protein interactions by providing many stable and symmetrical surfaces (3, 4). One reason why WDR domains may have been less studied than other common domains, such as kinases or PDZ or SH3 domains (3), is that no WDR domain has yet been found with catalytic activity (3), but this does not mean that the scaffold domains are less important. To the contrary, their serving as a platform for multiple enzymatic reactions and signaling events is highly significant (5).In recent years, human genetic studies have also begun to recognize the importance of WDR gen...

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. AbstractObjective: Early onset epileptic encephalopathy with suppression-burst is one of the most severe epilepsy phenotypes in human patients. A significant proportion of cases have a genetic origin, and the most frequently mutated gene is KCNQ2, encoding Kv7.2, a voltage-dependent potassium channel subunit, leading to so-called KCNQ2related epileptic encephalopathy (KCNQ2-REE). To study the pathophysiology of KCNQ2-REE in detail and to provide a relevant preclinical model, we generated and described a knock-in mouse model carrying the recurrent p.(Thr274Met) variant. Methods: We introduced the p.(Thr274Met) variant by homologous recombination in embryonic stem cells, injected into C57Bl/6N blastocysts and implanted in pseudopregnant mice. Mice were then bred with 129Sv Cre-deleter to generate heterozygous mice carrying the p.(Thr274Met), and animals were maintained on the 129Sv genetic background. We studied the development of this new model and performed in vivo electroencephalographic (EEG) recordings, neuroanatomical studies at different time points, and multiple behavioral tests. Results: The Kcnq2 Thr274Met/+ mice are viable and display generalized spontaneous seizures first observed between postnatal day 20 (P20) and P30. In vivo EEG recordings show that the paroxysmal events observed macroscopically are epileptic seizures. The brain of the Kcnq2 Thr274Met/+ animals does not display major structural defects, similar to humans, and their body weight is normal. Kcnq2 Thr274Met/+ mice have a reduced life span, with a peak of unexpected death occurring for 25% of the animals by 3 months of age. Epileptic seizures were generally not observed when animals grew older. Behavioral characterization reveals important deficits in spatial learning and memory in adults but no gross abnormality during early neurosensory development. | 869 MILH et aL.

This article describes a series of standard operating procedures for morphological phenotyping of the mouse brain using basic histology. Many histological studies of the mouse brain use qualitative approaches based on what the human eye can detect. Consequently, some phenotypic information may be missed. Here we describe a quantitative approach for the assessment of brain morphology that is simple and robust. A total of 78 measurements are made throughout the brain at specific and well-defined regions, including the cortex, the hippocampus, and the cerebellum. Experimental design and timeline considerations, including strain background effects, the importance of sectioning quality, measurement variability, and efforts to correct human errors are discussed. © 2016 by John Wiley & Sons, Inc.

Brain morphogenesis is an important process contributing to higher-order cognition, however our knowledge about its biological basis is largely incomplete. Here we analyze 118 neuroanatomical parameters in 1,566 mutant mouse lines and identify 198 genes whose disruptions yield NeuroAnatomical Phenotypes (NAPs), mostly affecting structures implicated in brain connectivity. Groups of functionally similar NAP genes participate in pathways involving the cytoskeleton, the cell cycle and the synapse, display distinct fetal and postnatal brain expression dynamics and importantly, their disruption can yield convergent phenotypic patterns. 17% of human unique orthologues of mouse NAP genes are known loci for cognitive dysfunction. The remaining 83% constitute a vast pool of genes newly implicated in brain architecture, providing the largest study of mouse NAP genes and pathways. This offers a complementary resource to human genetic studies and predict that many more genes could be involved in mammalian brain morphogenesis.

In this article, we present a standardized protocol for fast and robust neuroanatomical phenotyping of the adult mouse brain, which complements a previously published article (doi: 10.1002/cpmo.12) in Current Protocols in Mouse Biology. It is aimed at providing an experimental pipeline within an academic research setting from experimental work to data analysis. Our analysis focuses on one single parasagittal plane, covering the majority of brain regions involved in higher order cognitions such as the cortex, hippocampus, and cerebellum, for a total of 166 parameters of area, length, and cell-level measurements in contrast to 78 parameters in our previously published coronal screen. Benefits of using parasagittal analysis for large-scale neuroanatomic screens are discussed. © 2018 by John Wiley & Sons, Inc.

In previous work, mouse lines were selected for eight generations for resistance (R) or susceptibility (S) to endophyte-infected fescue toxicosis using depression in postweaning gain caused by a toxin-containing diet as the selection criterion. Characterizing biological changes associated with resistance or susceptibility in those mice might suggest genetic or therapeutic approaches to alleviate fescue toxicosis in cattle. The first objective of the current experiment was to determine whether the toxin-containing diet depressed reproduction and mature size more severely in S than in R mice. The second was to investigate line and diet effects on hepatic glutathione-S-epoxytransferase (GST) and uridine diphosphate glucuronosyl-transferase (UDPGT) activities and to relate enzyme activities to reproduction within line by diet groups. Twenty-eight pairs per line (S or R) x diet (toxin-containing [+] or toxin-absent [-]) group cohabitated for 36 wk. The + diet depressed the number of pups born and weaned and litter weight weaned (P < .01) within the first two litters produced. Diet effects were greatest early in the experiment. Percentage changes in reproduction caused by the + diet for R and S pairs, respectively, were -13 and -28 for total pups born, -10 and -25 for total pups weaned, -13 and -14 for total litters produced, and -30 and -42 for total litter weight weaned. The S line mice were heavier than R line mice on both diets, but the + diet had a larger depressing effect on mature size of S line than of R line males (line x diet interaction, P = .09) and females (interaction not significant). Averaged across diets, GST activity was higher in R than in S dams (P = .05) at 44 wk of age but was not affected by diet or line x diet. Activity of GST was correlated with number of pups born (-.50), number of litters produced (-.44), and survival percentage (.40) within the R- group; in the R+ group, GST activity was correlated only with survival percentage (.37). In the S- and S+ groups, GST activity was not correlated with any reproductive trait. Line, diet, and their interaction did not affect UDPGT activity, and UDPGT activity was not correlated with any reproductive trait in any line x diet group. Selected lines differed in response to a toxin-containing diet as measured by its effect on reproduction and mature size. The R and S mice also differed in GST activity, but GST activity was correlated with reproductive traits only in R-line mice.

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