[Recent advances on sex determining mechanisms of Microtus mandarinus].

Most mammalian sex determination belongs to male heterogametic type of genetic sex determination. Sex determination of most mammals depends on the Y chromosome. SRY gene is the testis-determining factor on Y chromosome of most mammals, which is thought to be the most important gene in sex determination by far.

[An overview of phylogenetic relationship between Mus and Microtus].

Muriod is the most successful one among rodents struggling for existence, and biologists have been paying much attention to it, especially Mus musculus. Because of the thorough study on Mus musculus, it has been widely applied in lab, and becomes a good material for studying other animals. Phylogenetic relationship between different species and populations of Mus and Microtus are more clearly revealed with some genetic markers of modern genetics, such as protein, mtDNA, and rDNA.

[A study on the karyotype, C-banding and Ag-NORs in Rana nigromaculata].

The chromosome samples of Rana nigromaculata were prepared by peripheral blood lymphocyte cultured in vitro. Karyotype, C-banding and silver-staining nucleolus organizer regions (Ag-NORs) were observed on chromosomes samples. The result showed that: (1) the chromosome number of Rana nigromaculata is 26 (2n=26), i.

[The effect of CSN1 S2, CSN3 and beta-lg genes on milk performance in Xinong Saanen dairy goat].

PCR-RFLP technique was applied to analyze correlation between the polymorphisms of CSN1 S2 (alpha(s2) casein), CSN3 (kappa casein) and beta-lg (beta-lactoglobulin) genes and milk performance in 69 individuals of Xinong Saanen dairy goat. The results showed that there was significant correlation between different genotypes of CSN1 S2 locus and milk yield:average milk yield of individuals with genotype FF was less than that of genotype NN (P < 0.05); the second lactation milk yield of individuals with genotype NN was over 90 kg higher than that with genotype FF (P < 0.

[A family history of vitiligo with autosomal dominant inheritance].

A family history of vitiligo was reported in this paper,and the reason causing disease was discussed. We think that the vitiligo in the family history is caused by autosomal dominant inheritance.

[Detection of Y chromosome in human and Microtus mandarinus with FISH].

The purpose of the investigation was to detect the Y chromosome of human and Microtus mandarinus with the satellite DNA probe in human's Yq by fluorescence in situ hybridization(FISH). We hybridizied the probe with the metaphase chromosome and interphase nucleus specimens of humanbeing and Microtus mandarinus respectively. The results showed that there was hybridization signal on metaphase chromosome and interphase nucleus of human, but no signal on metaphase chromosome and interphase nucleus of Microtus mandarinus.