Vertebrate features revealed in the rudimentary eye of the Pacific hagfish (Eptatretus stoutii).

ABSTRACT: Hagfish eyes are markedly basic compared to the eyes of other vertebrates, lacking a pigmented epithelium, a lens and a retinal architecture built of three cell layers: the photoreceptors, interneurons and ganglion cells. Concomitant with hagfish belonging to the earliest-branching vertebrate group (the jawless Agnathans), this lack of derived characters has prompted competing interpretations that hagfish eyes represent either a transitional form in the early evolution of vertebrate vision, or a regression from a previously elaborate organ. Here, we show the hagfish retina is not extensively degenerating during its ontogeny, but instead grows throughout life via a recognizable PAX6+ ciliary marginal zone. The retina has a distinct layer of photoreceptor cells that appear to homogene

SUBMITTER: Dong EM 

PROVIDER: S-EPMC7892416 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature