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Duan, A.

Publications and source records attributed to Duan, A..

2 recordsLinked to original sources
bioRxiv2022

Unbiased stereologic estimates of dopaminergic and GABAergic neurons in the A10, A9, and A8 subpopulations in the young male Macaque

The ventral midbrain is the primary source of dopamine- (DA) expressing neurons in most species. GABA-ergic and glutamatergic cell populations are intermixed among DA-expressing cells and purported to regulate both local and long-range dopamine neuron activity. Most work has been conducted in rodent models, however due to evolutionary expansion of the ventral midbrain in primates, the increased size and complexity of DA subpopulations warrants further investigation. Here, we quantified the number of DA neurons, and their GABA-ergic complement in classic DA cell groups A10 (midline ventral tegmental area nuclei [VTA] and parabrachial pigmented nucleus [PBP]), A9 (substantia nigra, pars compacta [SNc]) and A8 (retrorubral field [RRF]) in the macaque. Because the PBP is a disproportionately expanded feature of the A10 group, and has unique connectional features in monkeys, we analyzed A10 data by dividing it into classic midline nuclei and the PBP. Unbiased stereology revealed total putative DA neuron counts to be 210,238 +/- 17,127 (A10 = 110,319 +/- 9,649, A9= 87,399 +/-7,751 and A8=12,520 +/- 827). Putative GABAergic neurons were fewer overall, and evenly dispersed across the DA subpopulations (GAD67= 71,215 +/- 5,663; A10=16,836 +/- 2,743; A9=24,855 +/- 3,144 and A8=12,633 +/- 3,557). Calculating the GAD67/TH ratio for each subregion revealed differential balances of these two cell types across the DA subregions. The A8 subregion had the highest complement of GAD67-positive neurons compared to TH-positive neurons (1:1), suggesting a potentially high capacity for GABAergic inhibition of DA output in this region. HIGHLIGHTSO_LIThe A10 subregion expands laterally and caudally in nonhuman primates C_LIO_LIThe A10, A9, and A8 comprise 52%, 42% and 6% of DA neurons, respectively C_LIO_LIGABAergic neurons are more evenly dispersed across subregions C_LIO_LIThe A8 subpopulation has the highest ratio of GABA: DA neurons C_LI

neuroscience↗
bioRxiv2019

Genome-wide analysis reveals genetic diversity, linkage disequilibrium, and selection for milk traits in Chinese buffalo breeds

Water buffalo holds the tremendous potential of milk and meat that widespread throughout central and southern China. However, characterization of the population genetics of Chinese buffalo is poorly understood. Using Axiom(R) buffalo genotyping array, we performed the genetic diversity, linkage disequilibrium (LD) pattern and signature of selection in the 176 Chinese buffaloes from thirteen breeds. A total of 35,547 SNPs passed quality control and were used for further analyses. Population genetic analysis revealed a clear separation between the swamp and river types. Ten Chinese indigenous breeds clustered into the swamp group, Murrah and Nili-Ravi breeds were the river group, and the crossbred breed was closer to the river group. Genetic diversity analysis showed that the swamp group had a lower average expected heterozygosities compared to the river group. LD decay distance was much shorter in the swamp group compared with the river group with [Formula] value of approximately 50 Kb. Analysis of runs of homozygosity indicated that extensive remote and recent inbreeding activity was respectively found within swamp and river groups. Moreover, a total of 12 genomic regions under selection were detected between river and swamp groups. Further, 12 QTL regions were found associated with buffalo milk production traits. Some candidate genes within these QTLs were predicted to be involved in the cell structure and function, suggesting that these genes might play vital roles in the buffalo milk performance. Our data contribute to our understanding of the characterization of population genetics in Chinese buffaloes, which in turn may be utilized in buffalo breeding programs.\n\nAuthor SummaryIdentifying the causal genes or markers associated with important economic traits in livestock is critical to increasing the production level on the species. However, current understanding of the genetic basis for milk production traits in buffalo is limited. Here, we confirmed the divergent evolution, distinct population structure, and LD extent among Chinese buffalo breeds. We also identified 12 QTL regions associated with milk production traits in buffaloes using the selective sweeps and haplotype analysis. Further, a total of 7 genes involved in the cell structure and function were predicted within the identified QTLs. These findings suggested that these genes can serve as the candidate genes associated with buffalo milk production, which hold a vital role in the milk trait improvement of dairy buffalo industry.

genetics↗