Embryonic Lethality, Juvenile Growth Variation, and Adult Sterility Correlate With Phylogenetic Distance of Danionin Hybrids.

Hybrid incompatibility, which plays a pivotal role in speciation, is expected to correlate with greater phylogenetic distance. Here, we investigate the fitness of interspecies hybrids within the Danionin subfamily, which includes the model species, Danio rerio, and its relatives - Danio kyathit, Danio albolineatus, Danio margaritatus, and Devario aequipinnatus. We generated hybrids through in vitro fertilization, using Danio rerio as the maternal species, with normal fertilization rates showing no incompatibilities in sperm-egg interactions within these two genera.

Conserved germ plasm characteristics across the Danio and Devario lineages.

In many animal species, germ cell specification requires the inheritance of germ plasm, a biomolecular condensate containing maternally derived RNAs and proteins. Most studies of germ plasm composition and function have been performed in widely evolutionarily divergent model organisms, such as Caenorhabditis elegans, Drosophila, Xenopus laevis, and Danio rerio (zebrafish). In zebrafish, 12 RNAs localize to germ plasm at the furrows of the early embryo.

Decoding an organ regeneration switch by dissecting cardiac regeneration enhancers.

Heart regeneration in regeneration-competent organisms can be accomplished through the remodeling of gene expression in response to cardiac injury. This dynamic transcriptional response relies on the activities of tissue regeneration enhancer elements (TREEs); however, the mechanisms underlying TREEs are poorly understood. We dissected a cardiac regeneration enhancer in zebrafish to elucidate the mechanisms governing spatiotemporal gene expression during heart regeneration.