Contribution Of Oocyte Research Articles

Novel key roles for structural maintenance of chromosome flexible domain containing 1 (Smchd1) during preimplantation mouse development.

Structural maintenance of chromosome flexible domain containing 1 (Smchd1) is a chromatin regulatory gene for which mutations are associated with facioscapulohumeral muscular dystrophy and arhinia. The contribution of oocyte- and zygote-expressed SMCHD1 to early development was examined in mice ( Mus musculus) using a small interfering RNA knockdown approach. Smchd1 knockdown compromised long-term embryo viability, with reduced embryo nuclear volumes at the morula stage, reduced blastocyst cell number, formation and hatching, and reduced viability to term. RNA sequencing analysis of Smchd1 knockdown morulae revealed aberrant increases in expression of a small number of trophectoderm (TE)-related genes and reduced expression of cell proliferation genes, including S-phase kinase-associated protein 2 ( Skp2). Smchd1 expression was elevated in embryos deficient for Caudal-type homeobox transcription factor 2 ( Cdx2, a key regulator of TE specification), indicating that Smchd1 is normally repressed by CDX2. These results indicate that Smchd1 plays an important role in the preimplantation embryo, regulating early gene expression and contributing to long-term embryo viability. These results extend the known functions of SMCHD1 to the preimplantation period and highlight important function for maternally expressed Smchd1 messenger RNA and protein.

Genetic studies on the Pacific abalone. XVI. Differential contribution of oocytes to triploid offsprings due to maternal genotypes at multiple loci in the Pacific ablone.

Quantitative analyses of genotypic relationships between parents and their diploid and triploid offspring sib populations, induced by inhibiting release of first or second polar body, have made it possible to estimate rate ofgene-centromere recombination at phosphogluconate dehydrogenase and phosphoglucomutase loci and to disclose differential contribution of oocytes to triploid offspring, in relation to the latter locus in the Pacific abalone Haliotis discus hannai. In the present work, application ofthe similar analyses on parentage of genotypic compositions allowed to estimate rate of gene-centromere recombination and fitness or differential contribution of oocytes to triploid offspring at each of the loci coding electrophoretic and thermostability variations of phosphoglucose isomerase and esterase and to discuss probable integrated effect of genotypes at multiple loci of parental female animals on their relative contribution in production of triploid offsprings.