.JPG)
Claim · model-written summary
The older sex-linked stratum S1 is dated to 6.3-7.6 million years ago.
.JPG?width=60){kind=small}
HippophaeVerbatim
t0“Heteromorphic XY chromosomes with pericentromeric recombination suppression in Hippophae (Elaeagnaceae)”
e2“Both sex chromosome pairs have an older (S1, 6.3-7.6 million years ago (Ma)) and a younger stratum (S2, 1.9-2.5 Ma), the latter with more species-specific inversions”
Title
Yiling Li; Deyan Wang; Pengchuan Sun; et al. New Phytologist 2026. doi:10.1111/nph.71059
Other claims from this paper (9)
- Observation In H. rhamnoides the X chromosome is 30% larger than the Y.
- Observation In H. tibetana the X chromosome is 15% larger than the Y.
- Mechanism The larger X chromosome of H. rhamnoides is due mainly to repetitive sequence accumulation on the X and extensive gene loss on the Y.
- Observation The younger sex-linked stratum S2 is dated to 1.9-2.5 Ma.
- Observation The younger stratum S2 has more species-specific inversions than S1.
- Observation The sex-linked regions coincide with the pericentromere regions in Hippophae.
- Observation The pericentromere regions were greatly enlarged in the ancestor of Hippophae by the insertion of another chromosome.
- Observation Dosage compensation occurs primarily in the floral tissues of Hippophae.
- Mechanism Dosage compensation in Hippophae occurs mainly through downregulation of female X-specific genes.