微小按蚊是泰国西部主要的疟疾传播媒介，其嗅觉通路中的基因变异与自然种群中的宿主寻找行为有关。

Genetic variation in olfactory pathways associated with host-seeking behavior in natural populations of Anopheles minimus, a primary malaria vector in western Thailand.

作者信息

Pusawang Kanchon, Zhong Daibin, Sriwichai Patchara, Samung Yudthana, Saeung Atiporn, Aupalee Kittipat, Somboon Pradya, Junkum Anuluck, Wongpalee Somsakul Pop, Saingamsook Jassada, Sattabongkot Jetsumon, Cui Liwang, Yan Guiyun

机构信息

Parasitology and Entomology Research Cluster (PERC), Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.

Department of Population Health and Disease Prevention, University of California, Irvine, CA, 92697, USA.

出版信息

Parasit Vectors. 2025 Sep 24;18(1):385. doi: 10.1186/s13071-025-07029-x.

DOI:10.1186/s13071-025-07029-x

PMID:40993777

Abstract

BACKGROUND

Malaria transmission hinges on infected Anopheles mosquitoes biting humans, with carbon dioxide (CO), host odor, and body heat acting as key attractants. Along the Thai-Myanmar border, Anopheles minimus (the Funestus Group), a primary malaria vector, exhibits a stronger preference for human hosts than species of the Maculatus Group. Elucidating the genetic basis of this feeding behavior is essential for improving malaria control strategies.

METHODS

Wild Anopheles mosquitoes were collected in Tha Song Yang district, Tak province, Thailand, from July 2019 to November 2020, using cow-baited traps, human landing catches, and Center for Disease Control (CDC) light traps. Specimens were identified morphologically and confirmed by Sanger sequencing of the cytochrome c oxidase subunit 1 (cox1) gene. We then performed whole-genome sequencing on An. minimus females categorized by host-seeking behavior: cow-baited collection (COW), human landing indoor (HLI), and human landing outdoor (HLO) to investigate the genetic determinants of host preference.

RESULTS

Anopheles minimus females accounted for 25% of total samples (504/1,997). Cox1 sequencing revealed 143 unique haplotypes among 287 specimens, forming two major phylogenetic lineages, A (181 sequences) and B (106 sequences), suggestive of potential cryptic diversity. Whole-genome sequencing of An. minimus Lineage A from COW, HLI, and HLO groups yielded 12,659,785 variants. After filtering, 68,975 non-synonymous single-nucleotide polymorphisms (nsSNPs) remained. Comparing allele frequencies across the three pooled groups (FDR-adjusted p-value < 0.001) yielded 2,629, 2,948, and 4,369 significant nsSNPs, respectively. Gene Ontology (GO) analysis of genes harboring these nsSNPs showed strong enrichment for olfaction-related terms. The top six nsSNPs with olfactory annotations from each group comparison were selected for validation; Sanger sequencing confirmed their association with host-seeking preference. The VectorBase gene IDs for these candidate nsSNPs are AMIN001807, AMIN001339, AMIN003886, AMIN000912, AMIN003926, AMIN011060, AMIN002342, and AMIN015480.

CONCLUSIONS

The observed significant genomic variance in field-collected An. minimus females, categorized by collection methods (reflecting host-seeking behavior), proposes a genetic underpinning for these behavioral variations. Differential nsSNPs within olfactory pathway genes might be functionally linked to host-seeking in this important malaria vector.

摘要

背景

疟疾传播取决于受感染的按蚊叮咬人类，二氧化碳（CO₂）、宿主气味和体温是关键的吸引因素。在泰国-缅甸边境，微小按蚊（富氏按蚊组）是主要的疟疾传播媒介，与多斑按蚊组的物种相比，它对人类宿主表现出更强的偏好。阐明这种摄食行为的遗传基础对于改进疟疾控制策略至关重要。

方法

2019年7月至2020年11月，在泰国夜丰颂府的达府Song Yang区，使用牛诱饵诱捕器、人饵诱捕法和疾病控制中心（CDC）灯光诱捕器收集野生按蚊。通过形态学鉴定标本，并通过细胞色素c氧化酶亚基1（cox1）基因的桑格测序进行确认。然后，我们对按宿主寻找行为分类的微小按蚊雌性进行了全基因组测序：牛诱饵收集（COW）、室内人饵诱捕（HLI）和室外人饵诱捕（HLO），以研究宿主偏好的遗传决定因素。

结果

微小按蚊雌性占总样本的25%（504/1997）。Cox1测序在287个标本中揭示了143个独特的单倍型，形成了两个主要的系统发育谱系，A（181个序列）和B（106个序列），提示潜在的隐性多样性。来自COW、HLI和HLO组的微小按蚊A谱系的全基因组测序产生了12,659,785个变异。经过筛选，剩下68,975个非同义单核苷酸多态性（nsSNPs）。比较三个合并组的等位基因频率（FDR校正p值<0.001）分别产生了2,629、2,948和4,369个显著的nsSNPs。对含有这些nsSNPs的基因进行基因本体（GO）分析显示，嗅觉相关术语有很强的富集。从每组比较中选择前六个带有嗅觉注释的nsSNPs进行验证；桑格测序证实了它们与宿主寻找偏好的关联。这些候选nsSNPs的VectorBase基因ID是AMIN001807、AMIN001339、AMIN003886、AMIN000912、AMIN003926、AMIN011060、AMIN002342和AMIN015480。