title: Pattern of mutation rates in the germline of Drosophila melanogaster males from a large-scale mutation screening experiment.
abstract: The sperm or eggs of sexual organisms go through a series of cell divisions from the fertilized egg; mutations can occur at each division. Mutations in the lineage of cells leading to the sperm or eggs are of particular importance because many such mutations may be shared by somatic tissues and also may be inherited, thus having a lasting consequence. For decades, little has been known about the pattern of the mutation rates along the germline development. Recently it was shown from a small portion of data that resulted from a large-scale mutation screening experiment that the rates of recessive lethal or nearly lethal mutations differ dramatically during the germline development of Drosophila melanogaster males. In this paper the full data set from the experiment and its analysis are reported by taking advantage of a recent methodologic advance. By analyzing the mutation patterns with different levels of recessive lethality, earlier published conclusions based on partial data are found to remain valid. Furthermore, it is found that for most nearly lethal mutations, the mutation rate at the first cell division is even greater than previous thought compared with those at other divisions. There is also some evidence that the mutation rate at the second division decreases rapidly but is still appreciably greater than those for the rest of the cleavage stage. The mutation rate at spermatogenesis is greater than late cleavage and stem-cell stages, but there is no evidence that rates are different among the five cell divisions of the spermatogenesis. We also found that a modestly biased sampling, leading to slightly more primordial germ cells after the eighth division than those reported in the literature, provides the best fit to the data. These findings provide conceptual and numerical basis for exploring the consequences of differential mutation rates during individual development.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Gao
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Xue-Rong
authors.initials: XR
authors.lastname: Pan
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Wu
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Ye-Lin
authors.initials: YL
authors.lastname: Shao
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Shi-Meng
authors.initials: SM
authors.lastname: Ai
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
authors.forename: Shu-Qun
authors.initials: SQ
authors.lastname: Liu
authors.affiliation: Division of Biostatistics and Human Genetics Center, School of Public Health, The University of Texas at Houston, Houston, Texas.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Barton
authors.affiliation: Department of Biological Sciences, Bowling Green State University, Bowling Green, Ohio.
authors.forename: Ronny C
authors.initials: RC
authors.lastname: Woodruff
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Zhang
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China Department of Biological Sciences, Bowling Green State University, Bowling Green, Ohio yunxin.fu@uth.tmc.edu.
authors.forename: Yun-Xin
authors.identifier: http://orcid.org/0000-0002-1224-4075
authors.initials: YX
authors.lastname: Fu
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics*; D018095:Germ-Line Mutation; D008297:Male; D059645:Mutation Rate; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa
keywords: Drosophila melanogaster; cell coalescent; germline mutation rate; likelihood inference