No abstract

No abstract

Identifying the mechanism for sex determination in amphibians is challenging. Very little is known about sex determination mechanisms of Rana dybowskii, a species of importance to evolutionary and conservation biology. We screened for sex‐linked molecular markers in R. dybowskii in China using target region amplification polymorphism with 2 fixed primers against the sequences of Dmrt1. We found 2 male‐linked molecular markers in R. dybowskii, which were 222 bp and 261 bp long. The detection rates of 222 bp marker in males form Xinglong, Huadian, and Dandong were 93.79%, 69.64%, and 13.64%, respectively, while the rate in females from Huadian was 27.50%. Besides, the detection rates of 261 bp marker in the above 3 regions were only observed in males at the rate of 93.79%, 87.50%, and 32.73%, respectively. The inheritance patterns of sex‐linked molecular markers showed that the 2 sex‐linked molecular markers were heterozygous. Compared to the XY‐male parent, progeny from XX‐pseudo‐male parent possessed lower sex reversal ratio at the same rearing temperature, and the proportion of female froglets from an XX‐pseudo‐male parent was more than 95% at low rearing temperature (15°C). Our findings suggest that R. dybowskii displays male heterogamety, and the 2 sex‐linked molecular markers may have a guiding significance for the protection and utilization of R. dybowskii.

ABSTRACT. Nuclear mitochondrial pseudogenes (numts), originating from mtDNA insertions into the nuclear genome, have been detected in many species. However, the distribution of numts in the newly published nuclear genome of domestic goat (Capra hircus) has not yet been explored. We used the entire goat mtDNA sequence and nuclear genome, to identify 118 numts using BLAST. Of these, 79 were able to map sequences to the genome. Further analysis showed that the size of the numts ranged from 318 to 9608 bp, and the homologous identity between numts and their respective corresponding mtDNA fragments varied between 65 and 99%. The identified Yunnan black goat numts covered nearly all the mitochondrial genes including mtDNA control region, and were distributed over all chromosomes with the exception of chromosomes 18, 21, and 25. The Y chromosome was excluded from our analysis, as sequence data are currently not available. Among the discovered 79 numts that we were able to map to the genome, 26 relatively complete mitochondrial genes were detected. Our results constitute valuable information for subsequent studies related to mitochondrial genes and goat evolution.

No abstract