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.

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.

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Objective:The study aims toIn order to protect and utilize the genetic resources of Min pig, this paper uncovered the genetic diversity and unique genetic structure of the Min pig conserved population, divided the nucleus conservation population, and constructed the molecular pedigree. Methods: We used KPS Porcine Breeding Chip v1 50K for SNP detection of 94 samples (31♂，63♀) in the Min pig conserved population from Lanxi breeding Farm.A c c e p t e d A r t i c l e 3 Results: We showed that tThe polymorphic marker ratio (PN), the observed heterozygosity (Ho), and the expected heterozygosity (He) were 0.663, 0.335 and 0.330, respectively. The pedigree-based inbreeding coefficients (FPED) was significantly different from those estimated from runs of homozygosity (FROH) and single nucleotide polymorphism (FSNP) based on genome, . but Tthe pearson correlation coefficient between FROH and FSNP was significant (P < 0.05). The effective population content (Ne) showed a continuously decreasing trend. The rate of decline was the slowest from 200 to 50 generations ago (r = 0.95), then accelerated slightly from 50 to 5 generations ago (1.40 < r < 1.50), and increased significantly in the last 5 generations (r = 2.6). According to the composition of Chinese lineage, we separated the nucleus conservation population (81 individuals) and the candidate conservation population (13 individuals) of Min pig, then the nucleus conservation population of Min pig was divided into 9 families by genomic information matrix. Conclusion:The results illuminated thatOur study indicated that the genetic diversity of the Min pig conserved population was inadequate. Due to the introgression of European commercial pig breeds and the unscientific breeding process, it is necessary for Min pig to construct the molecular pedigree of the nucleus conservation population.