Newswise \u2014 The most dangerous animal in the world just got easier to study\u2014and perhaps defeat one day.<\/p>\n
Researchers from Rockefeller University\u2019s Laboratory of Neurogenetics and Behavior<\/a>, in collaboration with mosquito experts around the globe, have created the first-ever cellular atlas of the Aedes aegypti mosquito, which transmits more diseases than any other species of its kind. The Mosquito Cell Atlas provides cellular-level resolution of gene expression in every mosquito tissue, from the antennae down to the legs. The dataset<\/a> is freely available to all researchers (and curious members of the public). They recently published<\/a> the atlas in Cell.<\/p>\n \u201cThis is a comprehensive snapshot of what every cell in the mosquito is doing as far as expressing genes,\u201d says lab head Leslie Vosshall, who has studied Aedes aegypti, aka the yellow fever mosquito, for nearly two decades. \u201cIt\u2019s a real achievement because we profiled so many different types of tissues in both males and females.\u201d<\/p>\n The atlas has already yielded new insights into the genetic secrets of Aedes aegypti, including novel cell types, subtle differences\u2014and unexpected similarities\u2014between male and female mosquitoes, and the dramatic changes in genetic expression that the female mosquito brain undergoes after a blood feeding.<\/p>\n Senior author Nadav Shai, a senior scientist in both Vosshall\u2019s lab and at the Howard Hughes Medical Institute, anticipates that by using the atlas as a starting point, many researchers will make new discoveries. \u201cWe believe this enormous data set will really move mosquito biology forward,\u201d he says. \u201cIt\u2019s a great tool for vector biologists to take whatever interests them and just run with their own line of research.\u201d<\/p>\n Organ by organ<\/strong><\/p>\n In the past several years, scientists have used single-cell sequencing to identify cell types and illuminate gene expression patterns in model organisms such as Drosophila melanogaster (fruit fly), Caenorhabditis elegans (nematode), and Mus musculus (mouse), resulting in a whole organism, single-cell atlas of each species.<\/p>\n Mosquito researchers have been following suit but in a piecemeal way: organ by organ, tissue by tissue, all in different studies. Some of that prior work was done by Vosshall\u2019s team and fellow members of the Aedes aegypti Mosquito Cell Atlas Consortium, a global collaboration of scientists that was assembled for this project.<\/p>\n Most prior studies had focused on female mosquitoes, leaving out males. \u201cBoth females and males feed on nectar in their day-to-day lives, but females need blood for protein to develop their eggs and produce a new generation of mosquitoes,\u201d says first author Olivia Goldman.<\/p>\n \u201cBecause the female is the one that\u2019s spreading all the pathogens, there is an enormous bias toward looking at the biology of the female and very little information about the male,\u201d Vosshall says. \u201cSo we wanted to be inclusive and fill in the gap.\u201d<\/p>\n \u201cWe also wanted to bring the mosquito cell biology up to date in a single resource using advanced and uniform sequencing technology,\u201d Shai says.<\/p>\n To that end, the team used single-nucleus RNA sequencing (snRNA-seq)\u2014which excels at capturing the biology of all insect cell types compared to single cell approaches\u2014to create a large dataset of more than 367,000 nuclei from 19 types of mosquito tissues selected across five biological themes: major body segments; sensation and host seeking; viral infection; reproduction; and the central nervous system.<\/p>\n Tasting sweetness with their legs<\/strong><\/p>\n They found 69 cell types grouped into 14 major cell categories, many of which had never been seen before.<\/p>\n Among the most striking findings was the pervasiveness of polymodal sensory neurons\u2014supercharged cells that can pick up a wide variety of environmental cues, including temperature and taste. Previous research from the Vosshall lab had found that the antenna and maxillary palps were packed with these neurons, but now that they were able to look organism-wide, they found them everywhere, including the nose, tongue, and legs.<\/p>\n \u201cJust like the antennae and maxillary palps, the legs and mouth parts have really powerful tools for sensing the world,\u201d Shai says. \u201cTogether they enable mosquitoes to be really good at what they do\u2014seek hosts, feed on them, and reproduce.\u201d<\/p>\n Those multifunctional chemoreceptors allow them to, among other things, detect sweetness and fresh water.<\/p>\n \u201cBeing able to taste sweetness with their legs may be useful for detecting sugars, which both females and males need to live,\u201d Shai says. \u201cBut it\u2019s just one part of a combination of tastes that clues them into what\u2019s around them\u2014a human to bite, a flower for sugar source or a good water source to lay eggs. We believe that the combination of a lot of sensors is important for their survival.\u201d<\/p>\n Brain changes that accompany behavior shifts<\/strong><\/p>\n After feeding, a female mosquito loses all interest in humans and other hosts; her focus becomes developing and laying eggs.<\/p>\n \u201cHow does this incredibly strong drive to bite people get turned off?\u201d Vosshall says.<\/p>\n \u201cWe knew from previous research from our lab and others that the brain transcripts change after blood feeding, and our assumption was that maybe we would find different subtypes of neurons that down- or upregulated their transcripts,\u201d Shai says.<\/p>\n To find out, they examined the gene expression of female mosquito brains at 3, 12, 24, and 48 hours after a blood feeding. They found dramatic changes in gene expression in all time periods, which peaked after the first few hours and gradually abated. Most of the early expression changes were of genes being upregulated, while later time periods showed a mix of both up- and downregulation.<\/p>\n Strikingly, these changes occurred in a completely unexpected way. Neurons account for roughly 90% of mosquito brain cells, but it was the glia\u2014support cells that account for less than 10%\u2014that underwent large shifts in gene expression.<\/p>\n \u201cThe glia are completely rewired during this time when the females lose interest in people,\u201d Vosshall says.<\/p>\n \u201cThat was a big surprise,\u201d Shai says. \u201cIt\u2019s evidence that glia are super important for not only supporting brain cells and function but also are physiologically relevant to behavior.\u201d<\/p>\n Limited sexual dimorphism<\/strong><\/p>\n Another illuminating finding is that for all the documented morphological and behavioral differences between female and male mosquitoes, their cellular makeup is largely identical, aside from small clusters of sex-specific cells and reproductive organs.<\/p>\n \u201cWe were kind of expecting it to be a tale of two genomes, but that\u2019s not what we found,\u201d Vosshall says.<\/p>\n \u201cIn general, most cells look the same, and the transcripts they express are similar,\u201d Shai notes. \u201cHowever, that doesn\u2019t mean that the regulation and level of expression are the same, and those probably drive the differences. Another factor could be how the different gene expressions work together to create new functions.\u201d<\/p>\n One exception was found exclusively in the male antenna, which is largely unexplored. \u201cA small group of cells is marked by the expression of a single gene that\u2019s not expressed in any female tissue,\u201d Vosshall says. \u201cIf we hadn\u2019t compared male and female gene expression, we never would\u2019ve spotted them.\u201d Their function remains to be determined.<\/p>\n Future directions<\/strong><\/p>\n The Vosshall lab will mine the mosquito single-cell atlas to further its investigations into behavior such as host seeking and sensing the environment through Aedes aegypti\u2019s remarkable, widely dispersed set of multifunctional sensory neurons.<\/p>\n \u201cDifferent people in the lab are going to take it to different places,\u201d Shai says.<\/p>\n They hope that researchers everywhere will find it equally inspiring. \u201cThe sheer size of the dataset opens up many new avenues of research that people couldn\u2019t study before because they didn\u2019t have this tool,\u201d Shai says.<\/p>\n \u201cThis is a global resource that has been open to everyone since the very inception of the project in 2021, so many people are already using it,\u201d Vosshall adds. \u201cWe\u2019re excited to see the discoveries that will come from it.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Newswise \u2014 The most dangerous animal in the world just got easier to study\u2014and perhaps defeat one day.…\n","protected":false},"author":2,"featured_media":154660,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77],"tags":[7260,7580,18,3015,7261,4799,19,17,90408,941,35154,133],"class_list":{"0":"post-154659","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-all-journal-news","9":"tag-cell-biology","10":"tag-eire","11":"tag-environmental-health","12":"tag-environmental-science","13":"tag-global-warming","14":"tag-ie","15":"tag-ireland","16":"tag-mosquitomosquito-aedes-aegyptimosquito-controlgene-expressionmosquito-cell-atlas","17":"tag-newswise","18":"tag-rockefeller-university","19":"tag-science"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/115467037191255687","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/154659","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=154659"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/154659\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/154660"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=154659"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=154659"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=154659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}