The majority of lizards classified in the superfamily Iguanoidea have an XX/XY sex-determination system in which sex-chromosomal linkage shows homology with chicken (Gallus gallus) chromosome 15 (GGA15). However, the genomics of sex chromosomes remain largely unexplored owing to the presence of homomorphic sex chromosomes in majority of the species. Recent advances in high-throughput genome complexity reduction sequencing provide an effective approach to the identification of sex-specific loci with both single-nucleotide polymorphisms (SNPs) and restriction fragment presence/absence (PA), and a better understanding of sex chromosome dynamics in Iguanoidea. In this study, we applied Diversity Arrays Technology (DArTseq^TM) in 29 phenotypic sex assignments (14 males and 15 females) of green iguana (Iguana iguana). We confirmed a male heterogametic (XX/XY) sex determination mode in this species, identifying 29 perfectly sex-linked SNP/PA loci and 164 moderately sex-linked SNP/PA loci, providing evidence probably indicative of XY recombination. Three loci from among the perfectly sex-linked SNP/PA loci showed partial homology with several amniote sex chromosomal linkages. The results support the hypothesis of an ancestral super-sex chromosome with overlaps of partial sex-chromosomal linkages. However, only one locus among the moderately sex-linked loci showed homology with GGA15, which suggests that the specific region homologous to GGA15 was located outside the non-recombination region but in close proximity to this region of the sex chromosome in green iguana. Therefore, the location of GGA15 might be further from the putative sex-determination locus in green iguana. This is a paradigm shift in understanding linkages on homomorphic X and Y sex chromosomes. The DArTseq platform provides an easy-to-use strategy for future research on the evolution of sex chromosomes in Iguanoidea, particularly for non-model species with homomorphic or highly cryptic sex chromosomes.

归类于鬣蜥科的大多数蜥蜴具有XX / XY性别决定系统，其中性别-染色体连锁表现出与鸡的同源性（鸡鸡）15号染色体（GGA15）。然而，由于大多数物种中存在同型性染色体，因此性染色体的基因组学在很大程度上尚未得到开发。高通量基因组复杂性降低测序的最新进展为鉴定具有单核苷酸多态性（SNPs）和限制性片段存在/不存在（PA）的性别特异性基因座提供了一种有效的方法，并且可以更好地了解人类中性染色体的动态鬣蜥 在这项研究中，我们将多样性阵列技术（DArTseq ^TM）应用到了绿鬣蜥的29个表型性别分配中（男性14位，女性15位）（鬣蜥）。我们证实了该物种的雄性异配子性（XX / XY）性别决定模式，确定了29个完全性相关的SNP / PA基因座和164个中等性相关的SNP / PA基因座，提供了可能表明XY重组的证据。完全由性别连接的SNP / PA基因座中的三个基因座显示出部分同源性，与几个羊膜性染色体连锁有关。这些结果支持了具有部分性染色体连接重叠的祖先超性染色体的假说。但是，在中等性别连接的基因座中只有一个基因座显示与GGA15同源，这表明与GGA15同源的特定区域位于非重组区域之外，但在绿鬣蜥中紧邻性染色体的该区域。因此，GGA15的位置可能离绿鬣蜥的推定性别决定基因座更远。这是理解同型X和Y性染色体上的连锁的范式转变。DArTseq平台为将来在鬣蜥科中性染色体的进化研究提供了一种易于使用的策略，特别是对于具有同态或高度隐秘性染色体的非模型物种。