QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Martianov, I. Articles by Sassone-Corsi, P. Search for Related Content PubMed PubMed Citation Articles by Martianov, I. Articles by Sassone-Corsi, P.

Distinct functions of TBP and TLF/TRF2 during spermatogenesis: requirement of TLF for heterochromatic chromocenter formation in haploid round spermatids

Igor Martianov^1,, Stefano Brancorsini^1,, Anne Gansmuller¹, Martti Parvinen², Irwin Davidson^1, and Paolo Sassone-Corsi^1,

¹ Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS/INSERM/ULP, B.P. 163, 67404 Illkirch Cédex, C.U. de Strasbourg, France
² Department of Anatomy, University of Turku, 20520 Turku, Finland
These authors contributed equally to this work

View larger version (44K): [in a new window]   Fig. 1. Developmental regulation of TBP and TLF. (A) RNase protection experiments. The RNA used is indicated above each lane and the detected transcripts identified are listed to the right of each panel. Lane 1 shows a control with only tRNA. (B) The origin of the RNA, pachytene spermatocytes (spermatocytes), and haploid spermatids (spermatids) is shown above each lane and the transcripts are listed to the right of each panel. (C) Immunodetection of TBP, TLF and CREM. The stage-specific protein extracts used are indicated above each lane and the locations of TBP, TLF and the CREM isoforms are indicated to the right of each panel.

View larger version (61K): [in a new window]   Fig. 2. (A,B) Expression of TLF and TBP in seminiferous tubules of wild-type (A) and TLF null-mice (B). The upper panel in each section shows the immunodetection of TLF and TBP as indicated. The middle and lower panels show the corresponding Hoechst stained DNA and merged images. 40x magnification.

View larger version (90K): [in a new window]   Fig. 3. (A-D) Immunodetection of TBP and TLF in developing male germ cells. TLF and TBP are detected in microdissected segments of seminiferous tubules from various stages as indicated above each panel. Representative examples of cell types are indicated. PS, pachytene spermatocytes; RS, haploid round spermatids; ES, elongating spermatids; EES, early elongating spermatids; LS, leptotene spermatocytes; ZS, zygotene spermatocytes. 40x magnification.

View larger version (72K): [in a new window]   Fig. 4. (A-C) Immunodetection of TBP and TLF in developing male germ cells. The layout and abbreviations are as described in Fig. 3.

View larger version (61K): [in a new window]   Fig. 5. (A,B) Summary of TLF and TBP expression during spermatogenesis. The spermatogenic wave is schematised and the representative cell types are indicated. Expression of TLF is indicated in A by the red colouring and that of TBP in B by the green colouring.

View larger version (61K): [in a new window]   Fig. 6. Different intracellular localisations of TBP and TLF. (A) Confocal images of sectioned seminiferous tubules stained with antibodies against TLF (upper panels) or TBP (lower panels) as indicated. A single representative section is shown. RS, haploid round spermatids; ES, elongating spermatids; C, the chromocenter. The lower panel shows perinuclear TBP detected in late stage elongated spermatids. (B) Confocal sections of pachytene spermatocytes (PS) stained with TLF or TBP as indicated. In all panels the middle and right hand images show the corresponding Hoechst stained DNA and merged images respectively. 400x magnification.

View larger version (140K): [in a new window]   Fig. 7. Live germ cell cytology in microdissected segments of seminiferous tubules from wild-type (WT) and TLF–/– (–/–) mice. (A) Stage VII segment from a wild-type mouse. (B,C) Stage VII segments from a TLF–/– mouse. (D) Stage VI segment from a TLF–/– mouse. EA and LA, early and late apoptotic round spermatids respectively; C, chromocenter; S, Sertoli cell. A, acrosome. Ap, apoptotic round spermatids; D degenerating round spermatids. ES16. Step 16 elongated spermatid. 1000x magnification.

View larger version (114K): [in a new window]   Fig. 8. Electron microscopic sections of wild-type and TLF–/– seminiferous tubules. (A-I) High magnification views of defective acrosome formation. (J) Wild-type and (K) mutant cell showing position of organelles. (A) Normal acrosome in wild-type spermatids; (B-E) defective acrosome in round spermatids; (F-G) acrosome in early wild-type or mutant elongating spermatids; (H-I) defective acrosome in late step 13 wild-type or mutant elongating spermatids. AG, acrosomal granule; G, Golgi; N, nucleolus; V, vacuole; C, chromocenter; A, acrosome. B shows a close-up of the acrosome of the cell shown in K. A,C-G: 4000x magnification; B,H-K, 5000x magnification.

View larger version (81K): [in a new window]   Fig. 9. Immunodetection of fibrillarin and HP1 in wild-type and TLF mutant spermatids. (A) Immunodetection of fibrillarin in wild-type (above) and mutant (below) spermatids. Representative nucleoli (N) and chromocenters (C) are indicated. (B) Immunodetection of HP1. Nomenclature is as described in A.