De Novo Transcriptomic and Life-History Responses of Moina Micrura Under Stress Environment Conditions

Moina micrura represents a promising model species for ecological and ecotoxicological investigations in tropical freshwater ecosystems. Illumina NovaSeq (TM) 6000 sequencing was employed in this study to analyze M. micrura across three distinct developmental stages: juvenile, adult, and male. Current study successfully annotated 51,547 unigenes (73.11%) derived from seven (7) different databases. A total of 554 genes were found to be significantly upregulated, while 452 genes showed significant downregulation between juvenile and male. Moreover, 1001 genes were upregulated, whereas 830 genes exhibited downregulation between the adult and male. Analysis of differentially expressed genes revealed upregulation of chitin, cuticle, myosin (MYO), mitogen-activated protein kinases (MAPK), fibrillin (FBN), cytochrome (CYP), glutathione s-transferase (GST), vitellogenin (VTG), acetylcholinesterase (AChE), and transforming growth factor beta (TGFB) under unfavorable environmental conditions (male), as compared to favorable environmental conditions (juveniles and adults). These alterations in gene expression significantly impact the phenological and life-history traits of M. micrura. Furthermore, the upregulation of hemoglobin (HMB), doublesex (DSX), juvenile hormone analogs (JHA), heat shock protein (HSP), and methyltransferase (METT) genes in males initiates the sex-switching effects observed in M. micrura. These findings hold substantial value for researchers interested in determining M. micrura sequences for future investigations of gene expression and comparative reproductive genome analysis within the Moina genus and cladoceran families.

Automated summary

M. micrura was analyzed using Illumina NovaSeq (TM) 6000 sequencing, revealing differential gene expression patterns across developmental stages. A total of 51,547 genes were annotated, with 554 genes upregulated and 452 genes downregulated between juveniles and males, and 1001 genes upregulated and 830 genes downregulated between adults and males. Gene expression analysis identified several genes involved in chitin, cuticle, muscle proteins, mitogen-activated protein kinases, fibrillin, cytochrome, glutathione s-transferase, vitellogenin, acetylcholinesterase, and transforming growth factor beta that were upregulated under unfavorable environmental conditions (males). Additionally, the upregulation of hemoglobin, doublesex, juvenile hormone analogs, heat shock protein, and methyltransferase genes in males initiated sex-switching effects. These findings have significant implications for future investigations of gene expression and reproductive genome analysis in the Moina genus.