bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.06.09.658756

Trpv4 mediates temperature induced sex change in ricefield eel

Abstract

The ricefield eel (Monopterus albus), an economically important aquaculture species in China, is a freshwater teleost fish that exhibits protogynous hermaphroditism. Although progress has been made in understanding the sex determination and differentiation of this species, the underlying mechanisms remain unclear. Here we show that warm temperature promotes gonadal transformation by up-regulating testicular differentiation genes such as dmrt1/sox9a in ovaries. Trpv4, a Ca2+-permeable cation channel expressed in gonadal somatic cells, is highly sensitive to ambient temperature and links environmental temperature to testicular differentiation in ricefield eel. In female fish reared at cool temperature, injection of Trpv4 agonist into the ovaries leads to a significant up-regulation of male pathway genes, and in female fish exposed to warm temperature, Trpv4 inhibition or trpv4 siRNA knockdown suppresses warm temperature-induced male gene expression. pStat3 signaling is downstream of Trpv4 and transduces Trpv4-controlled calcium signaling into the sex determination cascades. Inhibition of pStat3 activity prevents the up-regulation of testicular differentiation genes by warm temperature treatment and ovarian injection of Trpv4 agonist, whereas activation of pStat3 is sufficient to induce the expression of male genes, in the presence of Trpv4 antagonist. pStat3 binds and activates jmjd3/kdm6b, an activator of the dmrt1 gene. Consistently, ovarian injection of Kdm6b inhibitor blocks the up-regulation of testicular differentiation genes by warm temperature exposure. We propose that environmental factors, such as temperature, promote gonadal transformation of ricefield eel by inducing the expression of male pathway genes in ovaries via the Trpv4-pStat3-Kdm6b-dmrt1 axis. Our results provide new insights into the molecular mechanism underlying natural sex change of ricefield eel, which will be useful for sex control in aquaculture. HighlightsO_LIWarm temperature promotes gonadal transformation of ricefield eel C_LIO_LITrpv4 links environmental temperature and the sex determination pathway C_LIO_LIpStat3 is downstream of Trpv4-controlled calcium signaling C_LIO_LIpStat3 binds and activates kdm6b/jmjd3 C_LI

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yang, Z., Luo, T., Zhang, Y., Sun, Y.. 2025-06-13. Trpv4 mediates temperature induced sex change in ricefield eel. https://doi.org/10.1101/2025.06.09.658756

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A bicistronic Aldh1a3-P2A-TagBFP knock-in reporter mouse line for studying genitourinary tract development

Aldehyde dehydrogenase 1a3 (Aldh1a3) is an enzyme involved in retinoic acid synthesis with dynamic expression patterns during development, including in the urogenital system. Here, we generated a bicistronic Aldh1a3-P2A-TagBFP knock-in mouse using CRISPR/Cas9 genome editing, inserting TagBFP immediately upstream of the endogenous Aldh1a3 stop codon. Correct targeting was confirmed by Oxford Nanopore long-read sequencing, and heterozygous and homozygous mice were viable and fertile without overt morphological abnormalities. TagBFP fluorescence faithfully overlapped with endogenous Aldh1a3 immunoreactivity and reproduced established expression domains in the developing craniofacial region, intestine, kidney, and broader urogenital system. Extensive characterization of the urogenital system revealed dynamic, spatially restricted BFP reporter activity in Aldh1a3-expressing domains across several key structures, including the ureteric bud and collecting duct lineage, seminal vesicles, caput epididymis, and developing uterine horns. The Aldh1a3-P2A-TagBFP mouse provides a fluorescent resource for visualizing Aldh1a3 expression across development and in adult tissues, including for the characterization of Aldh1a3-expressing domains in the urogenital system. The relatively low fluorescence intensity of TagBFP should be considered when assessing low-level reporter expression.

developmental biology↗

Translation of a small upstream open reading frame functions as a rheostat for the regulation of lin-41 by the Let-7 microRNA in Caenorhabditis elegans

MicroRNAs have been likened to the "dark matter" of eukaryotic genomes, reflecting their pervasive regulatory influence. MicroRNAs were first identified through genetic studies of developmental timing in the nematode Caenorhabditis elegans. Let-7 was the first microRNA recognized to be broadly conserved. The principal target of Let-7 in the developmental timing pathway is the TRIM-NHL RNA-binding protein LIN-41. During the L4 larval stage, Let-7 represses lin-41 translation by binding to two Let-7 complementary sites in the lin-41 3'UTR. Despite the importance of microRNA-based translational regulation, the underlying molecular mechanisms are incompletely understood. Through genetic analysis, we discovered an unrecognized feature of the mechanism by which Let-7 controls lin-41 translation. This mechanism requires a 5'-regulatory exon containing a seven-amino acid upstream open reading frame (uORF) and conserved sequence elements. Genome editing indicates that the specific uORF amino acid sequence itself is not important. Our data suggest that uORF translation and 5'UTR structure limit initiation at the downstream lin-41 start codon, enabling tight control by Let-7. Without this mechanism, the Let-7 microRNA is unable to properly regulate lin-41 to enable proper development.

developmental biology↗

Ductal myofibroblasts reactivate contractile program to stabilize alveolar architecture during lung regeneration

The alveolar sac architecture is essential for efficient gas exchange and must be precisely maintained throughout life; however, how this delicate structure is preserved during adult regeneration remains poorly understood. Using a mouse pneumonectomy model, we found that Lgr6+ Hhip+ ductal myofibroblasts, a poorly characterized mesenchymal population, are indispensable for maintaining alveolar integrity during lung regrowth. Comprehensive characterization using single-cell transcriptomics, mouse genetics, and pharmacological assays demonstrated that these ductal myofibroblasts secrete myogenic factors, most notably CCN4, to reactivate a myogenic program that converts them into contractile PA-DMFs, thereby preserving alveolar architecture. Lineage-tracing further revealed that these ductal myofibroblasts originate from embryonic MCAM- SMA+ distal progenitors via subepithelial TGF-{beta} signaling, serving as a lifelong guardian of alveolar structural integrity. Notably, cross-species analysis identified an analogous population of LGR6+ fibromyocytes in human respiratory bronchioles. Together, these findings indicate ductal myofibroblasts as a developmentally programmed cell population that reactivate a contractile program to structurally support the regeneration of adult lungs.

developmental biology↗