Miller Emily J, Eldridge Mark D B, Cooper Desmond W, Herbert Catherine A
School of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, NSW 2052, Australia.
Reprod Fertil Dev. 2010;22(3):539-49. doi: 10.1071/RD09061.
Knowledge of the determinants of reproductive success is essential for understanding the adaptive significance of particular traits. The present study examined whether particular behavioural, morphological, physiological or genetic traits were correlated with male dominance and reproductive success using three semi-free-ranging captive populations (n = 98) of the eastern grey kangaroo (Macropus giganteus). The morphological traits measured included bodyweight, head, forearm, tail, pes and leg length, forearm and bicep circumference, and testis size. Blood samples were collected to determine serum testosterone concentrations. All individuals were typed for 10 microsatellite loci and paternity determined for each pouch young. To determine the influence of relatedness and genetic diversity on male reproductive success, internal relatedness, standardised heterozygosity and mean d(2) were calculated. Dominant males sired a significantly higher proportion of offspring than smaller, lower-ranked males and had higher testosterone concentrations. Males that sired offspring were significantly heavier and had larger body size. Sires were significantly more heterozygous and genetically dissimilar to breeding females than non-sires. Despite the wealth of knowledge on the social organisation of kangaroos, this is the first study to assign parentage and male reproductive success using molecular evidence.
了解繁殖成功的决定因素对于理解特定性状的适应性意义至关重要。本研究使用东部灰袋鼠（大袋鼠属）的三个半自由放养圈养种群（n = 98），研究了特定的行为、形态、生理或遗传性状是否与雄性优势和繁殖成功相关。所测量的形态性状包括体重、头部、前臂、尾巴、足部和腿部长度、前臂和二头肌周长以及睾丸大小。采集血样以测定血清睾酮浓度。对所有个体进行10个微卫星位点分型，并确定每个育儿袋幼崽的父系。为了确定亲缘关系和遗传多样性对雄性繁殖成功的影响，计算了内部亲缘关系、标准化杂合度和平均d(2)。优势雄性所产后代的比例明显高于体型较小、地位较低的雄性，且睾酮浓度更高。成功繁殖后代的雄性明显更重，体型更大。与未成功繁殖的雄性相比，成功繁殖的雄性与繁殖雌性的杂合度更高，遗传差异更大。尽管对袋鼠的社会组织已有丰富的了解，但这是第一项利用分子证据确定亲子关系和雄性繁殖成功的研究。
