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.

Mutation of profilin 1 (PFN1) can cause amyotrophic lateral sclerosis (ALS). To assess how PFN1 mutation causes the disease, we created transgenic rats with human genomic DNA that harbors both the coding and the regulatory sequences of the human PFN1 gene. Selected transgenic lines expressed human PFN1 with or without the pathogenic mutation C71G at a moderate and a comparable level and in the similar pattern of spatial and temporal expression to rat endogenous PFN1. The artificial effects of arbitrary transgene expression commonly observed in cDNA transgenic animals were minimized in PFN1 transgenic rats. Expression of the mutant, but not the wild type, human PFN1 in rats recapitulated the cardinal features of ALS including the progressive loss of motor neurons and the subsequent denervation atrophy of skeletal muscles. Detergent-insoluble PFN1 inclusions were detected as the first pathology in otherwise asymptomatic transgenic rats expressing mutant human PFN1.The findings suggest that protein aggregation is involved in the neurodegeneration of ALS associated with PFN1 mutation. The resulting rat model is useful to mechanistic study on the ALS.

No abstract

Subcutaneous adipose tissue is a loose connective tissue specializing in the regulation of energy storage and metabolization. In domesticated pigs (Sus scrofa), the temporal development of subcutaneous adipose tissue is critical for meat production. However, the regulation of adipose tissue development remains unclear. Here, the subcutaneous adipose tissue development was characterized and compared in lean (Danish-Landrace) and obese (Min) pigs at juvenile and the juvenile-to-adult growth stages. Using RNA sequencing, we profiled the transcriptome of subcutaneous adipose tissue isolated from 4- and 16-week-old pigs and identified 24,718 expressed transcription units. Of them, 6327 genes were differentially expressed between the breeds and/or developmental stages. Compared with obese pigs, upregulated genes in lean pigs showed significant function and pathway enrichment in fatty acid degradation and mitochondrial functions. Further analysis uncovered the distinct usage preferences of the three alternative peroxisome proliferator-activated receptor γ (PPARγ) promoters associated with the development of subcutaneous adipose tissue in both breeds. Transcriptome analysis of subcutaneous adipose tissue in lean and obese pigs suggested that marker-assisted selection of fatty acid degradation and PPARγ signaling pathways could be important directions for future pork quality improvement and modern breeding.