1
|
Su J, Zhang Y, Su H, Wang C, Wang D, Yang Y, Li X, Qi W, Li H, Li X, Song Y, Cao G. Dosage Compensation of the X Chromosome during Sheep Testis Development Revealed by Single-Cell RNA Sequencing. Animals (Basel) 2022; 12:ani12172169. [PMID: 36077890 PMCID: PMC9454834 DOI: 10.3390/ani12172169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/09/2022] [Accepted: 08/17/2022] [Indexed: 11/18/2022] Open
Abstract
Simple Summary Male and female mammals carry the same complement of autosomes but differ with respect to their sex chromosomes: females carry XX chromosomes and males carry XY chromosomes. The evolutionary loss of genes from the Y chromosome led to a disparity in the dosage of X chromosomes versus autosomal genes, with males becoming monosomic for X-linked gene products. An imbalance in gene expression may have detrimental consequences. In males, X-linked genes need to be upregulated to levels equal to those of females, which is called dosage compensation. The existence of dosage compensation in germ cells is controversial. In testis, dosage compensation is thought to cease during meiosis. Some studies showed that the X chromosome is inactivated during meiosis and premature transcriptional inactivation of the X and Y chromosome during mid-spermatogenesis is essential for fertility. However, some studies failed to find support for male germline X inactivation. Using single-cell RNA seq data, in this study, we presented a comprehensive transcriptional map of sheep testes at different developmental stages and found that germ cell types in sheep testes show X-chromosome expression similar to that in the autosomes. The dosage compensation of germ cells at different stages was analyzed. MSL complex members are expressed in female flies and orthologs exist in many species, where dosage compensation mechanisms are absent or fundamentally different. This suggests that the MSL complex members also function outside of the dosage compensation machinery. Studies have shown that MSL complex can regulate mammalian X inactivation and activation. Abstract Dosage compensation is a mechanism first proposed by Susumu Ohno, whereby X inactivation balances X gene output between males (XY) and females (XX), while X upregulation balances X genes with autosomal gene output. These mechanisms have been actively studied in Drosophila and mice, but research regarding them lags behind in domestic species. It is unclear how the X chromosome is regulated in the sheep male germline. To address this, using single-cell RNA sequencing, we analyzed testes in three important developmental stages of sheep. We observed that the total RNA per cell from X and autosomes peaked in SSCs and spermatogonia and was then reduced in early spermatocytes. Furthermore, we counted the detected reads per gene in each cell type for X and autosomes. In cells experiencing dose compensation, close proximity to MSL (male-specific lethal), which is regulated the active X chromosome and was observed. Our results suggest that there is no dose compensation in the pre-meiotic germ cells of sheep testes and, in addition, MSL1 and MSL2 are expressed in early germ cells and involved in regulating mammalian X-chromosome inactivation and activation.
Collapse
Affiliation(s)
- Jie Su
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
- Department of Psychosomatic Medicine, Inner Mongolia Medical University, Hohhot 010030, China
| | - Yue Zhang
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Hong Su
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Caiyun Wang
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Daqing Wang
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Yanyan Yang
- Inner Mongolia Academy of Agriculture & Animal Husbandry Sciences, Hohhot 010000, China
| | - Xiunan Li
- Inner Mongolia Academy of Agriculture & Animal Husbandry Sciences, Hohhot 010000, China
| | - Wangmei Qi
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Haijun Li
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
| | - Xihe Li
- Inner Mongolia Saikexing Institutes of Breeding and Reproductive Biotechnologies in Domestic Animal, Hohhot 011517, China
- Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University, Hohhot 010021, China
| | - Yongli Song
- Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University, Hohhot 010021, China
- Correspondence: (Y.S.); (G.C.); Tel.: +86-133-6601-7565 (Y.S.); +86-138-4812-0488 (G.C.)
| | - Guifang Cao
- Inner Mongolia Key Laboratory of Basic Veterinary Science, Inner Mongolia Agriculture University, Hohhot 010018, China
- Correspondence: (Y.S.); (G.C.); Tel.: +86-133-6601-7565 (Y.S.); +86-138-4812-0488 (G.C.)
| |
Collapse
|
2
|
Duan JE, Flock K, Jue N, Zhang M, Jones A, Seesi SA, Mandoiu I, Pillai S, Hoffman M, O'Neill R, Zinn S, Govoni K, Reed S, Jiang H, Jiang ZC, Tian XC. Dosage Compensation and Gene Expression of the X Chromosome in Sheep. G3 (BETHESDA, MD.) 2019; 9:305-314. [PMID: 30482800 PMCID: PMC6325915 DOI: 10.1534/g3.118.200815] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022]
Abstract
Ohno's hypothesis predicts that the expression of the single X chromosome in males needs compensatory upregulation to balance its dosage with that of the diploid autosomes. Additionally, X chromosome inactivation ensures that quadruple expression of the two X chromosomes is avoided in females. These mechanisms have been actively studied in mice and humans but lag behind in domestic species. Using RNA sequencing data, we analyzed the X chromosome upregulation in sheep fetal tissues from day 135 of gestation under control, over or restricted maternal diets (100%, 140% and 60% of National Research Council Total Digestible Nutrients), and in conceptuses, juvenile, and adult somatic tissues. By computing the mean expression ratio of all X-linked genes to all autosomal genes (X:A), we found that all samples displayed some levels of X chromosome upregulation. The degrees of X upregulation were not significant (P-value = 0.74) between ovine females and males in the same somatic tissues. Brain, however, displayed complete X upregulation. Interestingly, the male and female reproduction-related tissues exhibited divergent X dosage upregulation. Moreover, expression upregulation of the X chromosome in fetal tissues was not affected by maternal diets. Maternal nutrition, however, did change expression levels of several X-linked genes, such as sex determination genes SOX3 and NR0B1 In summary, our results showed that X chromosome upregulation occurred in nearly all sheep somatic tissues analyzed, thus support Ohno's hypothesis in a new species. However, the levels of upregulation differed by different subgroups of genes such as those that are house-keeping and "dosage-sensitive".
Collapse
Affiliation(s)
| | | | - Nathanial Jue
- School of Natural Sciences, California State University, Monterey Bay, Seaside, CA 93955
| | - Mingyuan Zhang
- Department of Animal Science
- Laboratory Animal Center, Guangxi Medical University, Nanning 530021, China
| | | | - Sahar Al Seesi
- Smith College Department of Computer Science, Northampton, MA 01063
- Department of Computer Science
| | | | | | | | - Rachel O'Neill
- Department of Molecular and Cell Biology, and University of Connecticut, Storrs, CT, 06269
| | | | | | | | - Hesheng Jiang
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China, and
| | - Zongliang Carl Jiang
- Department of Animal Science
- School of Animal Science, Louisiana State University, Baton Rouge, LA 70803
| | | |
Collapse
|