Selective Heterozygous Advantage of Carriers of с.-23+1G>A Mutation in GJB2 Gene Causing Autosomal Recessive Deafness 1A.

We present the results of analysis of skin epidermis thickness in individuals with recessive mutation c.-23+1G>A in the GJB2 gene in comparison with individuals without this mutation living in Eastern Siberia (Yakut population). We examined 152 individuals with different genotypes by GJB2 gene mutation c.-23+1G>A. Homozygotes and heterozygotes by c.-23+1G>A have thicker epidermal layer (0.245 mm and 0.269 mm, respectively) in comparison with individuals without this mutation (0.193 mm) (p<0.05). The obtained data support the hypothesis about selective advantage of carriers of mutant GJB2 gene alleles and partly explain extremely high carrier frequency (10.3%) of c.-23+1G>A mutation in the GJB2 gene in Yakut population in Eastern Siberia.

[Mutagenic effect of radiation on mice, subjected to gamma-irradiation during the embryonic period. III. Frequency of coat color mosaics among mice, heterozygous for recessive mutations, subjected to irradiation during the early periods of embryogenesis]. / Mutagennyi effekt radiatsii u myshei, podvergshikhsia gamma-oblucheniiu v émbrional'nyi period. Soobshchenie III. Chastota mozaikov po okraske shersti sredi geterozigotnykh po retsessivnym mutatsiiam myshei, podvergshikhsia oblucheniiu v raznye sroki émbriogeneza

The frequency of coat colour and coat length mosaics was investigated among heterozygous for 7 or 6 recessive mutations mice, that were gamma-irradiated at doses of 100 or 200 r at different stages of embryogenesis. Only 4 mosaics with gray coat spots were found among 1399 animals that developed from embryos irradiated at doses of 100--200 r within 4,5--13,5 days of embryogenesis. 3 of these mosaics were found among 756 animals irradiated at the dose of 100 r at the 10,5 day of embryogenesis (0,35%). This frequency is considerably lower that the frequency of coat colour mosaics obtained by other authors in similar experiments.

[Mutagenic effect of radiation on mice subjected to gamma irradiation during the embryonic period. I. Frequency of reciprocal translocations in the spermatocytes of mice subjected to gamma-irradiation at different stages of embryogenesis]. / Mutagennyi éffekt radiatsii u myshei, podvergshikhsia gamma-oblucheniiu v émbrional'nyi period. Soobshchenie I. Chastota retsiproknykh translokatsii v spermatotsitakh myshei, podvergshikhsia gamma-oblucheniiu v raznye sroki émbriogeneza

The frequency of reciprocal translocations was investigated in spermatocytes of mice gamma-irradiated at doses of 100 or 200 r at 4,5; 8,5; 10,5; 11,5 and 13,5 days of embryonic development, and in spermatocytes of adult males whose spermatogonia were irradiated. The cytological analysis of 41 males that were irradiated at a dose of 200 r at 4,5 days of embryogenesis showed that 2 males had a high frequency of reciprocal translocations in both testes (on the average 20,6 and 28,8%). In the testes of other males of this group translocations were not detected. It is highly probably that the testes of these 2 males were heterozygous for reciprocal translocations. The yield of reciprocal translocations in spermatocytes of males irradiated at 8,5--13,5 days of embryogenesis was very low, and was only 0,67 +/- 0,2 x 10(-5) on the average per 1 r per cell, whereas for adult mice it was 12,5 +/- 3,0 x 10(5) per 1 r per cell.