{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T20:37:43Z","timestamp":1767904663669,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2024,3,12]],"date-time":"2024-03-12T00:00:00Z","timestamp":1710201600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000923","name":"Australian Research Council Centre of Excellence for Biotechnology and Development","doi-asserted-by":"publisher","award":["CE0348239"],"award-info":[{"award-number":["CE0348239"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>Stem cell maintenance and differentiation can be regulated via the differential activity of transcription factors within stem cells and their progeny. For these factors to be active, they need to be transported from their site of synthesis in the cytoplasm into the nucleus. A tissue-specific requirement for factors involved in nuclear importation is a potential mechanism to regulate stem cell differentiation. We have undertaken a characterization of male sterile importin alpha 1 (D\u03b11) null alleles in Drosophila and found that D\u03b11 is required for maintaining germline stem cells (GSCs) in the testis niche. The loss of GSCs can be rescued by ectopic expression of D\u03b11 within the germline but the animals are still infertile, indicating a second role for D\u03b11 in spermatogenesis. Expression of a D\u03b11 dominant negative transgene in GSCs confirmed a functional requirement for D\u03b11 in GSC maintenance but expression of the transgene in differentiating spermatogonia did not exhibit a phenotype indicating a specific role for D\u03b11 within GSCs. Our data indicate that D\u03b11 is utilized as a regulatory protein within GSCs to facilitate nuclear importation of proteins that maintain the stem cell pool.<\/jats:p>","DOI":"10.3390\/cells13060494","type":"journal-article","created":{"date-parts":[[2024,3,12]],"date-time":"2024-03-12T12:17:16Z","timestamp":1710245836000},"page":"494","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Drosophila Importin Alpha 1 (D\u03b11) Is Required to Maintain Germline Stem Cells in the Testis Niche"],"prefix":"10.3390","volume":"13","author":[{"given":"James","family":"Heaney","sequence":"first","affiliation":[{"name":"Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC 3010, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-8719-2702","authenticated-orcid":false,"given":"Jiamin","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC 3010, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Franca","family":"Casagranda","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC 3010, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5750-8046","authenticated-orcid":false,"given":"Kate L.","family":"Loveland","sequence":"additional","affiliation":[{"name":"Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia"},{"name":"Department of Molecular and Translational Sciences, Monash University, Clayton, VIC 3800, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicole A.","family":"Siddall","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC 3010, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gary R.","family":"Hime","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC 3010, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,3,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1186\/s12964-021-00741-y","article-title":"Types of nuclear localization signals and mechanisms of protein import into the nucleus","volume":"19","author":"Lu","year":"2021","journal-title":"Cell Commun. 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