Tdrd6 is required for spermiogenesis, chromatoid body architecture, and regulation of miRNA expression.
BACKGROUND
Chromatoid bodies (CBs) are characteristic spermatid organelles, which were suggested to function in RNA storage and small RNA processing but whose functions remain largely unknown. CB components include Mili, Miwi, and Tudor domain proteins such as Tdrd6, whose contribution to CB structure and function is elusive.


RESULTS
We determined gametogenesis stage- and male-specific expression and localization of Tdrd6, identified a C-terminally truncated form as predominant after meiosis I, and demonstrated direct physical interaction of Tdrd6 with the CB components Mili and Miwi. Development from round into elongated spermatids is abrogated in Tdrd6(-/-) mice. Their round spermatids bear "ghost" CBs, whose architecture is greatly disrupted. Mael, Miwi, and Mvh do not localize to the Tdrd6-deficient CBs, but retrotransposons are not significantly activated. However, more than 50 miRNAs are more abundant in Tdrd6(-/-) testes, as are exemplary pre- and pri-miRNAs.


CONCLUSIONS
We conclude that Tdrd6 is essential for spermiogenesis, for CB structure, and for proper mature and precursor miRNA expression.
Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
Ana
A
Vasileva
Daniela
D
Tiedau
Adriana
A
Firooznia
Thomas
T
Müller-Reichert
Rolf
R
Jessberger
D000818:Animals; D060565:Argonaute Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D015388:Organelles / Q000648:ultrastructure*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D013087:Spermatids / Q000502:physiology / Q000648:ultrastructure*; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000378:metabolism
D060565:Argonaute Proteins; D018797:Cell Cycle Proteins; D035683:MicroRNAs; C448522:Piwil1 protein, mouse; C448521:Piwil2 protein, mouse; D011506:Proteins; D012322:RNA Precursors; D012261:Ribonucleoproteins; C438001:Smc1l2 protein, mouse; C517521:TDRD6 protein, mouse