Evolution of the regulation of developmental gene expression in blind Mexican cavefish

Development, Journal Year: 2024, Volume and Issue: 151(20)

Published: Aug. 9, 2024

ABSTRACT Developmental evolution and diversification of morphology can arise through changes in the regulation gene expression or protein-coding sequence. To unravel mechanisms underlying early developmental cavefish species Astyanax mexicanus, we compared transcriptomes surface-dwelling blind cave-adapted morphs at end gastrulation. Twenty percent transcriptome was differentially expressed. Allelic ratios cave X surface hybrids showed that cis-regulatory are quasi-exclusive contributors to inter-morph variations expression. Among a list 108 genes with change level, explored control rx3, which is master eye gene. We discovered cellular rx3 levels cis-regulated cell-autonomous manner, whereas domain size depends on non-autonomous Wnt Bmp signalling. These results highlight how uncoupled regulatory modules shape morphological changes. Finally, transcriptome-wide search for fixed coding mutations differential exon use suggested sequence have minor contribution. Thus, during embryogenesis, main drivers evolution.

Language: Английский

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Elevated Blood Hemoglobin in Different Cavefish Populations Evolves Through Diverse Hemoglobin Gene Expression Patterns

Journal of Experimental Zoology Part B Molecular and Developmental Evolution, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

ABSTRACT Cave‐dwelling animals thrive in isolated caves despite the pressures of darkness, starvation, and reduced oxygen. Prior work revealed that Astyanax cave‐dwelling morphs derived from different cave localities express significantly higher levels blood hemoglobin compared to surface‐dwelling fish. Interestingly, this elevation is maintained populations cavefish, captive rearing normal oxygen conditions. We capitalized on consistent response elevated which were geographically distinct regions, determine if underpinned by expression same Hb genes. Blood proteins are encoded a large family ( ) gene members, demonstrate coordinated patterns, subject various organismal (e.g., period life history) environmental influences availability). Surprisingly, we found showed mostly divergent patterns expression. Cavefish two localities, Pachón Tinaja, have more recent shared origin, show similar as adults. However, during embryonic phases, Tinaja significant variability timing peak members. In sum, transcriptomic underpinnings represents complex composite across three cavefish populations. conclude these differential likely influenced history, unique conditions evolved.

Language: Английский

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The spatiotemporal and genetic architecture of extraoral taste buds in Astyanax cavefish

Communications Biology, Journal Year: 2024, Volume and Issue: 7(1)

Published: Aug. 6, 2024

Intense environmental pressures can yield both regressive and constructive traits through complex evolutionary mechanisms. Although regression is well-studied, the biological bases of features are less well understood. Cave-dwelling Astyanax fish harbor prolific extraoral taste buds on their heads, which absent in conspecific surface-dwellers. Here, we present novel ontogenetic data demonstrating appear gradually late life history. This appearance similar but non-identical different cavefish populations, where patterning has evolved to permit bud re-specification across endoderm-ectoderm germ layer boundary. Quantitative genetic analyses revealed that spatially distinct head primarily mediated by two cave-dominant loci. While precise function this expansion unknown, coincides with a dietary shift from live-foods bat guano, suggesting an adaptive mechanism detect nutrition food-starved caves. work provides fundamental insight feature, arising history, promising new window into unresolved vertebrate sensory organ development. Long-term developmental studies reveal develop history populations cave-dwelling fish, principal

Language: Английский

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Long-term hybridization in a karst window reveals the genetic basis of eye loss in cavefish

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 28, 2024

Eye loss is a hallmark trait of animals inhabiting perpetual darkness, such as caves. The Mexican tetra (

Language: Английский

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