Gonads in Histiostoma mites (Acariformes: Astigmata): Structure and development |
| |
| Institution: | 1. Department of Comparative Anatomy, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland;2. Institute of Biology, Pedagogical University, Podbrzezie 2, 31-358 Kraków, Poland;1. Bladder Cancer Center, Dana-Farber Cancer Institute, Boston, MA, USA;2. Harvard Medical School, Boston, MA, USA;1. Medical Faculty, University of Maribor, Taborska ulica 8, SI–2000 Maribor, Slovenia;2. Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koro?ka cesta 160, SI–2000 Maribor, Slovenia;3. Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia;1. Dipartimento di Fisica, Università della Calabria, and Istituto Nazionale di Fisica Nucleare, Gruppo c. Cosenza, 87036 Arcavacata di Rende (Cs), Italy;2. MTA-DE “Lendület” Functional Analysis Research Group, Institute of Mathematics, University of Debrecen, H-4010 Debrecen, P.O. Box 12, Hungary;1. Università degli Studi di Firenze, Dipartimento di Biologia, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Firenze, Italy;2. Università degli Studi di Firenze, Dipartimento di Biologia, Via La Pira 4, 50121 Firenze, Italy;1. University of Alaska Fairbanks, School of Fisheries and Ocean Sciences, 245 O?Neill Building, Fairbanks, AK 99775, USA;2. National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, 7600 Sand Point Way, Seattle, WA 98115, USA;3. Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, ME 04544, USA;4. Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02992-1197, USA;5. Department of Environmental Sciences, Huxley College of the Environment, Western Washington University, Bellingham, WA 98225-9181, USA;6. Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, P.O. Box 455672, 3737 Brooklyn Ave. NE, Seattle, WA 98105-5672, USA;7. Bermuda Institute of Ocean Sciences, 17 Biological Lane, St. Georges, Bermuda GE01, USA;8. Chespeake Biological Laboratory, University of Maryland Center for Environmental Science, P.O. Box 38, Solomons, MD 20688, USA |
| |
| Abstract: | The development of male and female gonads in arrhenotokous and thelytokous species of Histiostoma was studied using transmission electron microscopy (TEM). All instars were examined: larvae, protonymphs, facultative heteromorphic deutonymphs (=hypopi), tritonymphs, and adults. In testis primordium, spermatogonia surrounding a testicular central cell (TCC) with a gradually enlarging, branched nucleus are present already at the larval stage. Spermatogonia and the TCC are connected via narrow, tubular intercellular bridges revealing that the TCC is a germline cell. Spermatocytes appear at the protonymphal stage. At the heteromorphic deutonymph stage, the testis primordium is similar to that of the protonymph, but in the tritonymph it is much larger and composed as in the adult: spermatids as well as sperm cells are present. The latter are congregated ventrally in the testis at the entrance of the deferent duct.In the larval ovary, an eccentrically located ovarian nutritive cell (ONC) is surrounded by oogonia which are connected with the ONC via tubular intercellular bridges. In later stages, the ovary grows and oocytes appear in the protonymph. Meiotic synaptonemal complexes in oocytes occur from the tritonymph stage. At about the time of the final molting, tubular intercellular bridges transform into peculiar diaphragm-crossed bridges known only in Histiostoma mites. In the adult female, growing oocytes at the end of previtellogenesis lose intercellular bridges and move ventro-laterally to the ovarian periphery towards the oviduct entrance. Vitellogenesis occurs in oviducts.Germinal cells in both the testis and ovary are embedded in a few somatic stroma cells which may be well discernible already in the larval ovary; in the testis, somatic stroma cells are evident not earlier than the end of the tritonymphal stage. The ovary has a thin wall of flat somatic cells, whereas the testis is covered by a basal lamina only.The obtained results suggest that gonads in Histiostoma and other Astigmata originate from two primordial cells only. |
| |
| Keywords: | Testis Ovary Gonadal development Germinal cells Intercellular bridges Ovarian nutritive cell Testicular central cell Histiostomatidae “Acari” |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
