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miR-430 microRNA Family in Fishes: Molecular Characterization and Evolution
Claudio A Jiménez-Ruiz1, Roberto de la Herrán1, Francisca Robles1
1Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain.
Abstract:
The miR-430 microRNA family has been described in multiple fish species as one of the first microRNAs expressed by the zygote. It has been suggested that this family is implicated in maternal mRNA elimination, but may also play a role in steroidogenesis, sexual differentiation, and flatfish metamorphosis. The miR-430 sequences have been found in multiple-copy tandem clusters but evidence of their conservation outside of teleost fishes is scarce. In the present study, we have characterized the tandem repeats organization of these microRNAs in different fish species, both model and of interest in aquaculture. A phylogenetic analysis of this family has allowed us to identify that the miR-430 duplication, which took place before the Chondrostei and Neopterygii groups' divergence, has resulted in three variants ("a", "b", and "c"). According to our data, variant "b" is the most closely related to the ancestral sequence. Furthermore, we have detected isolated instances of the miR-430 repeat subunit in some species, which suggests that this microRNA family may be affected by DNA rearrangements. This study provides new data about the abundance, variability, and organization of the miR-430 family in fishes.
Insights
The miR-430 microRNA family in fish plays roles in early development and metamorphosis. This study reveals its evolutionary history, identifying three variants and suggesting DNA rearrangements impact its organization.
Area of Science:
- Developmental Biology
- Genomics
- Evolutionary Biology
Background:
- The miR-430 microRNA family is among the first expressed by fish zygotes.
- It is potentially involved in maternal mRNA elimination, steroidogenesis, sexual differentiation, and flatfish metamorphosis.
- miR-430 sequences are typically found in tandem clusters, with limited evidence of conservation outside teleost fishes.
Purpose of the Study:
- To characterize the tandem repeat organization of the miR-430 microRNA family in diverse fish species.
- To investigate the evolutionary history and conservation of the miR-430 family.
- To understand the variability and organization of miR-430 in fish.
Main Methods:
- Tandem repeat organization characterization in various fish species.
- Phylogenetic analysis of the miR-430 family.
- Detection of miR-430 repeat subunits.
Main Results:
- The miR-430 family originated from a duplication event predating the divergence of Chondrostei and Neopterygii, yielding three variants (a, b, c).
- Variant 'b' is the most closely related to the ancestral miR-430 sequence.
- Isolated miR-430 repeat subunits were found in some species, indicating potential DNA rearrangements.
Conclusions:
- The miR-430 family exhibits significant variability and complex organization in fish.
- Phylogenetic analysis clarifies the evolutionary relationships and duplication events within the miR-430 family.
- The findings contribute new insights into the abundance, variability, and genomic organization of fish microRNAs.
