Molecular Characterization of SCRBQ2 Gene in Anopheles stephensi from Pakistan and Its Expression Dynamics After Blood Feeding: Implications for Malaria Transmission Control
DOI:
https://doi.org/10.65761/jbs.v2.i1.6Keywords:
Anopheles stephensi, SCRBQ2, Malaria transmission, Midgut receptor, Blood-feedingAbstract
Background: Malaria remains a major public health challenge in Pakistan, with Anopheles stephensi serving as a primary urban vector. The croquemort-scavenger receptor class B2 (SCRBQ2) has been implicated in mediating Plasmodium invasion of the mosquito midgut and is considered a potential target for transmission-blocking strategies.
Objective: This study aimed to molecularly characterize the scrbq2 gene in A. stephensi from Karachi, Pakistan, and to investigate its tissue-specific and post-blood-meal expression dynamics.
Methods: A. stephensi adults (n = 335) were sampled and dissected to obtain midgut, fat body, salivary glands and ovaries. Ampification, sequencing, and submissions of the scrbq2 gene to GenBank (Accession ID: ON927345). In silico cloning and codon optimization were done to determine the potential of recombinant expression. Tissue-specific and temporal expression and changes during 0, 12, 26, 50, and 72 hours after blood meal (PBM) were determined by quantitative RT-PCR.
Findings: The scrbq2 gene has a 3068 bp coding sequence for a protein of 1022-amino-acid size with two fused CD36 competencies. A phylogenetic study showed great conservation among Anopheles species. The analysis of expression showed that the midgut was the most highly expressed followed by fat body, salivary glands and ovaries. The highest expression after blood meal was at 26 h PBM in the midgut and 50 h PBM in the fat body, which suggests a contribution to blood digestion and immune regulation.
Conclusion: The conserved domain architecture and dynamic expression of AsSCRBQ2 enables the consideration of this protein as an aspect of Plasmodium transmission alongside mosquito immunity. The results form the basis of the SCRBQ2-specific antiprequency interventions in Pakistan
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