Genomic conservation of erythropoietic microRNAs (erythromiRs) in white-blooded Antarctic icefish

摘要: White-blooded Antarctic crocodile icefish are the only vertebrates known to lack functional hemoglobin genes and red blood cells throughout their lives. We do not yet know, however, whether extinction of preceded loss or vice versa, nor erythropoiesis regulators disappeared along with in this erythrocyte-null clade. Several microRNAs, which we here call erythromiRs, expressed primarily developing zebrafish, mouse, humans. Abrogating some like mir144 mir451a, leads profound anemia, demonstrating a role erythropoiesis. Here, tested two mutually exclusive hypotheses: 1) that one more erythromiR extinguished erythropoietic program and/or led globin gene expression through pseudogenization; 2) were secondarily lost after icefish. explored small RNA transcriptomes generated from hematopoietic kidney marrow four notothenioids: red-blooded species (bullhead notothen Notothenia coriiceps emerald Trematomus bernacchii) white-blooded (blackfin Chaenocephalus aceratus hooknose Chionodraco hamatus). The N. genome assembly anchored analyses. Results showed that, species, blackfin possessed all erythromiRs. This result indicates was caused by genes. Furthermore, erythromiR, mir96, appears have been hemoglobin-expression detected organ but present All other erythromiRs investigated, including thus genomes at least Our results rule out hypothesis genomic any icefish, suggest cells, few experienced secondary loss. functions independent maintained thereby highlighting evolutionary resilience miRNA vertebrate genomes.