Figure 4

Proximal regions of the lep gene in H. sapiens. The figure shown depicts a region of H. sapiens chromosome 7 (126.0 to 129.4 Mb), for which the blue arrows indicate the orientation of genes along the chromosome. Arrows pointing to the right or left represent genes expressed from the positive or negative DNA strand, respectively. The relative position of the H. sapiens LEP gene is shown with red labeling. The black areas along the chromosome represent regions of co-linearity between H. sapiens and A. cygnoides that are generally considered to be conserved. The figure shows no co-linear regions near the LEP gene in H. sapiens. The dotted line represents A. cygnoides genes, which were distributed in different scaffolds, with the links determined based on the existence of homologous genes in adjacent regions of the H. sapiens chromosome. Numbers in the dashed boxes represent the number of homologous links of H. sapiens genes found in A. cygnoides (BLASTP: e value set to 1e^-5). The gaps in the dashed line represent corresponding genes in H. sapiens that lacked homologous genes in A. cygnoides. The diagram shows that during the evolutionary divergence of H. sapiens and A. cygnoides, genomic fragments near the lep gene may have been deleted from the goose genome, with the lep gene excluded from further replication as a result.