National Institute of Malaria Research, Dwarka, New Delhi, India.
National Institute of Malaria Research, Field Unit, Bengaluru, India.
PLoS One. 2022 Jul 21;17(7):e0270760. doi: 10.1371/journal.pone.0270760. eCollection 2022.
Anopheles stephensi, an invasive malaria vector, has been reported to have three biological forms identifiable mainly based on the number of ridges present on the egg's floats. Recently, the first intron of the odorant-binding protein-1 (AsteObp1) has been introduced as a molecular marker for the identification of these forms, and based on this marker, the presence of three putative sibling species (designated as species A, B and C) has been proposed. However, there is no data on the association of proposed markers with biological form or putative species on field populations.
Field collected and laboratory-reared An. stephensi were characterized for biological forms based on the number of ridges on the egg's float. DNA sequencing of the partial AsteObp1 gene of An. stephensi individuals were performed by Sanger's method, either directly or after cloning with a plasmid vector. Additionally, AsteObp1 sequences of various laboratory lines of An. stephensi were retrieved from a public sequence database.
AsteObp1 intron-1 in Indian An. stephensi populations are highly polymorphic with the presence of more than 13 haplotypes exhibiting nucleotides as well as length-polymorphism (90-to-121 bp). No specific haplotype or a group of closely related haplotypes of intron-1 was found associated with any biological form identified morphologically. High heterozygosity for this marker with a low inbreeding coefficient in field and laboratory populations indicates that this marker is not suitable for the delimitation of putative sibling species, at least in Indian populations.
AsteObp1 cannot serve as a marker for identifying biological forms of An. stephensi or putative sibling species in Indian populations.
已报道入侵性疟疾病媒按蚊斯氏按蚊具有三种生物型，主要依据卵浮器上脊的数量来区分。最近，气味结合蛋白-1（AsteObp1）的第一内含子已被引入作为识别这些形态的分子标记，基于该标记，提出了三种假定的姊妹种（命名为 A、B 和 C 种）。然而，关于拟议标记与野外种群生物型或假定种的关联尚无数据。
根据卵浮器上脊的数量对现场采集和实验室饲养的按蚊进行生物型特征分析。通过桑格法直接或在质粒载体克隆后，对按蚊个体的 AsteObp1 部分基因进行 DNA 测序。此外，从公共序列数据库中检索了各种实验室品系的按蚊 AsteObp1 序列。
印度按蚊种群中的 AsteObp1 内含子 1 高度多态性，存在 13 种以上的单倍型，表现出核苷酸和长度多态性（90-121bp）。在形态学上鉴定的任何生物型中都没有发现特定的单倍型或一组密切相关的内含子 1 单倍型。该标记在野外和实验室种群中表现出高度的杂合性和低近交系数，表明该标记不适合划分假定的姊妹种，至少在印度种群中不适合。
AsteObp1 不能作为鉴定印度按蚊生物型或假定姊妹种的标记。
