biostudies-literaturePeng Qthe National Waterfowl Industrial Technology Systemthe National Natural Science Foundation of China353https://www.ebi.ac.uk/biostudies/studies/S-EPMC6070456biostudies-literatureUnknown8(8)The genetic and molecular mechanisms of the flightless birds without limb modification are rarely reported. To explore the possible reasons for losing flight ability without limb modification, we used the domestic geese as an ideal model to preliminarily study the possible mechanisms for this kind of flightlessness. We compared the sequence variations of the exon 10 of <i>TSHR</i> gene between three domesticated geese populations and two wild ancestor populations. The results showed that domestic geese had higher genetic diversity and more complex population structure than their wild ancestors. We did not detect any population expansion in domestic geese population. However, we detected clear relaxed selection signal and positive selection in domesticated geese groups. Furthermore, special phylogenetic relationship of the exon 10 of <i>TSHR</i> was observed in domesticated geese groups. Combined with its well-established function on metabolic regulation and photoperiod control, we speculate that relaxed selection of <i>TSHR</i> might have effects on flightlessness of domesticated geese.3 BiotechHigh sequence variation in the exon 10 of <i>TSHR</i> gene is associated with flightless-domestic geese.PMC607045631660663311721812016YFD0500510CARS-43-4Lan DLiu YHe DHu YLi SPeng QLin ZWang YfalseHigh sequence variation in the exon 10 of <i>TSHR</i> gene is associated with flightless-domestic geese.The genetic and molecular mechanisms of the flightless birds without limb modification are rarely reported. To explore the possible reasons for losing flight ability without limb modification, we used the domestic geese as an ideal model to preliminarily study the possible mechanisms for this kind of flightlessness. We compared the sequence variations of the exon 10 of <i>TSHR</i> gene between three domesticated geese populations and two wild ancestor populations. The results showed that domestic geese had higher genetic diversity and more complex population structure than their wild ancestors. We did not detect any population expansion in domestic geese population. However, we detected clear relaxed selection signal and positive selection in domesticated geese groups. Furthermore, special phylogenetic relationship of the exon 10 of <i>TSHR</i> was observed in domesticated geese groups. Combined with its well-established function on metabolic regulation and photoperiod control, we speculate that relaxed selection of <i>TSHR</i> might have effects on flightlessness of domesticated geese.2018-01-01T00:00:00Z2018 Aug2026-05-05T23:16:49.106Z2019-08-07T07:01:41ZS-EPMC60704563010517810.1007/s13205-018-1371-3