Testis-specific ATP synthase peripheral stalk subunits required for tissue-specific mitochondrial morphogenesis in Drosophila.
In Drosophila early post-meiotic spermatids, mitochondria undergo dramatic shaping into the Nebenkern, a spherical body with complex internal structure that contains two interwrapped giant mitochondrial derivatives. The purpose of this study was to elucidate genetic and molecular mechanisms underlying the shaping of this structure.



The knotted onions (knon) gene encodes an unconventionally large testis-specific paralog of ATP synthase subunit d and is required for internal structure of the Nebenkern as well as its subsequent disassembly and elongation. Knon localizes to spermatid mitochondria and, when exogenously expressed in flight muscle, alters the ratio of ATP synthase complex dimers to monomers. By RNAi knockdown we uncovered mitochondrial shaping roles for other testis-expressed ATP synthase subunits.



We demonstrate the first known instance of a tissue-specific ATP synthase subunit affecting tissue-specific mitochondrial morphogenesis. Since ATP synthase dimerization is known to affect the degree of inner mitochondrial membrane curvature in other systems, the effect of Knon and other testis-specific paralogs of ATP synthase subunits may be to mediate differential membrane curvature within the Nebenkern.
Department of Biology, Davidson College, Davidson, NC, USA.
Eric M
EM
Sawyer
Department of Biology, Davidson College, Davidson, NC, USA.
Elizabeth C
EC
Brunner
Department of Biology, Davidson College, Davidson, NC, USA.
Yihharn
Y
Hwang
Department of Biology, Davidson College, Davidson, NC, USA.
Lauren E
LE
Ivey
Department of Biology, Davidson College, Davidson, NC, USA.
Olivia
O
Brown
Department of Biology, Davidson College, Davidson, NC, USA.
Megan
M
Bannon
Department of Biology, Davidson College, Davidson, NC, USA.
Dennis
D
Akrobetu
Department of Biology, Davidson College, Davidson, NC, USA.
Kelsey E
KE
Sheaffer
Department of Biology, Davidson College, Davidson, NC, USA.
Oshauna
O
Morgan
Department of Biology, Davidson College, Davidson, NC, USA.
Conroy O
CO
Field
Department of Biology, Davidson College, Davidson, NC, USA.
Nishita
N
Suresh
Department of Biology, Davidson College, Davidson, NC, USA.
M Grace
MG
Gordon
Department of Biology, Davidson College, Davidson, NC, USA.
E Taylor
ET
Gunnell
Department of Biology, Davidson College, Davidson, NC, USA.
Lindsay A
LA
Regruto
Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA.
Cricket G
CG
Wood
Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA.
Margaret T
MT
Fuller
Department of Biology, Davidson College, Davidson, NC, USA. kahales@davidson.edu.|Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA. kahales@davidson.edu.
Karen G
KG
Hales
D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology; D019143:Evolution, Molecular; D005426:Flight, Animal / Q000502:physiology; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009024:Morphogenesis; D018482:Muscle, Skeletal / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D010641:Phenotype; D010802:Phylogeny; D055503:Protein Multimerization; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D034622:RNA Interference; D013087:Spermatids / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000196:embryology*
D029721:Drosophila Proteins; C000618848:Knon protein, Drosophila; D021122:Protein Subunits; D049452:Green Fluorescent Proteins; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases
ATP synthase; Cristae; Drosophila melanogaster; Mitochondria; Spermatogenesis