摘要：Reef-building corals are declining due to environmental changes. Sacsin is a member of the heat shock proteins and has been reported as a candidate protein associated with the stress response in
Acropora corals. Recently, high nucleotide diversity and the persistence of two divergent haplogroups of sacsin-like genes in
Acropora millepora have been reported. While it was not clear when the two haplogroups have split and whether the haplogroups have persisted in only
A. millepora or the other lineages in the genus
Acropora. In this study, we analyzed a genomic region containing a sacsin-like gene from
Acropora and
Montipora species. Higher nucleotide diversity in the sacsin-like gene compared with that of surrounding regions was also observed in
A. digitifera. This nucleotide diversity is derived from two divergent haplogroups of a sacsin-like gene, which are present in at least three
Acropora species. The origin of these two haplogroups can be traced back before the divergence of
Acropora and
Montipora (119 Ma). Although the link between exceptionally high genetic variation in sacsin-like genes and functional differences in sacsin-like proteins is not clear, the divergent haplogroups may respond differently to envionmental stressors and serve in the adaptive phsiological ecology of these keystone species.
