scholarly journals Differential gene expression among three sex types reveals a MALE STERILITY 1 (CpMS1) for sex differentiation in papaya

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Dessireé Zerpa-Catanho ◽  
Jennifer Wai ◽  
Ming Li Wang ◽  
Li’ang Yu ◽  
Julie Nguyen ◽  
...  
Keyword(s):  
Sex Determination ◽  
Male Sterility ◽  
Flower Development ◽  
Sex Differentiation ◽  
Male Flower ◽  
Organ Development ◽  
Flower Buds ◽  
Flower Organ ◽  
Expression Of Genes ◽  
Development Processes

Abstract Background Carica papaya is a trioecious plant species with a genetic sex-determination system defined by sex chromosomes. Under unfavorable environmental conditions male and hermaphrodite exhibit sex-reversal. Previous genomic research revealed few candidate genes for sex differentiation in this species. Nevertheless, more analysis is still needed to identify the mechanism responsible for sex flower organ development in papaya. Results The aim of this study was to identify differentially expressed genes among male, female and hermaphrodite flowers in papaya during early (pre-meiosis) and later (post-meiosis) stages of flower development. RNA-seq was used to evaluate the expression of differentially expressed genes and RT-qPCR was used to verify the results. Putative functions of these genes were analyzed based on their homology with orthologs in other plant species and their expression patterns. We identified a Male Sterility 1 gene (CpMS1) highly up-regulated in male and hermaphrodite flower buds compared to female flower buds, which expresses in small male flower buds (3–8 mm), and that might be playing an important role in male flower organ development due to its homology to MS1 genes previously identified in other plants. This is the first study in which the sex-biased expression of genes related to tapetum development in the anther developmental pathway is being reported in papaya. Besides important transcription factors related to flower organ development and flowering time regulation, we identified differential expression of genes that are known to participate in ABA, ROS and auxin signaling pathways (ABA-8-hydroxylases, AIL5, UPBEAT 1, VAN3-binding protein). Conclusions CpMS1 was expressed in papaya male and hermaphrodite flowers at early stages, suggesting that this gene might participate in male flower organ development processes, nevertheless, this gene cannot be considered a sex-determination gene. Due to its homology with other plant MS1 proteins and its expression pattern, we hypothesize that this gene participates in anther development processes, like tapetum and pollen development, downstream gender specification. Further gene functional characterization studies in papaya are required to confirm this hypothesis. The role of ABA and ROS signaling pathways in papaya flower development needs to be further explored as well.

scholarly journals Discovery and Profiling of microRNAs at the Critical Period of Sex Differentiation in Xanthoceras sorbifolium Bunge

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1141
Author(s):  
Xu Wang ◽  
Yaqi Zheng ◽  
Shuchai Su ◽  
Yan Ao
Keyword(s):  
Seed Yield ◽  
Flower Development ◽  
Critical Period ◽  
Target Genes ◽  
Sex Differentiation ◽  
Male Flower ◽  
Differentially Expressed ◽  
Flower Buds ◽  
Xanthoceras Sorbifolium ◽  
Differentially Expressed Mirnas

Research Highlights: The critical period of sex differentiation in Xanthoceras sorbifolium was investigated. Multiple microRNAs (miRNAs) were identified to influence female and male flower development, with some complementary functions. Background and Objectives: Xanthoceras sorbifolium Bunge is widely cultivated owing to its multipurpose usefulness. However, as a monoecious plant, the low female–male flowers ratio and consequent low seed yield are the main bottlenecks for industrial-scale development of seed utilization. MiRNAs play crucial regulatory roles in flower development and sex differentiation; therefore, we evaluated the roles of miRNAs in the critical period of sex differentiation in X. sorbifolium. Materials and Methods: Four small RNA libraries for female and male flower buds of the critical period of sex differentiation were constructed from paraffin-embedded sections. The miRNAs were characterized by high-throughput sequencing, and differentially expressed miRNAs were validated by reverse transcription-quantitative polymerase chain reaction. Results: There were obvious differences in male and female pistil and stamen flower buds, with elongated inflorescence and clear separation of flower buds marking the critical period of sex differentiation. A total of 1619 conserved miRNAs (belonging to 34 families) and 219 novel miRNAs were identified. Among these, 162 conserved and 14 novel miRNAs exhibited significant differential expression in the four libraries, and 1677 putative target genes of 112 differentially expressed miRNAs were predicted. These target genes were involved in diverse developmental and metabolic processes, including 17 miRNAs directly associated with flower and gametophyte development, mainly associated with carbohydrate metabolism and glycan biosynthesis and metabolism pathways. Some miRNA functions were confirmed, and others were found to be complemented. Conclusions: Multiple miRNAs closely related to sex differentiation in X. sorbifolium were identified. The theoretical framework presented herein might guide sex ratio regulation to enhance seed yield.

scholarly journals Developmental basis for flower sex determination and effects of cytokinin on sex determination in Plukenetia volubilis (Euphorbiaceae)

2020 ◽  
Vol 33 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Yan Luo ◽  
Bang-Zhen Pan ◽  
Lu Li ◽  
Chen-Xuan Yang ◽  
Zeng-Fu Xu
Keyword(s):  
Sex Determination ◽  
Flower Development ◽  
Early Stage ◽  
Male Flower ◽  
Flower Initiation ◽  
Exogenous Application ◽  
Plukenetia Volubilis ◽  
Sacha Inchi ◽  
Male Flowers ◽  
Female Flowers

Key message Cytokinin might be an important factor to regulate floral sex at the very early stage of flower development in sacha inchi. Abstract Sacha inchi (Plukenetia volubilis, Euphorbiaceae) is characterized by having female and male flowers in a thyrse with particular differences. The mechanisms involved in the development of unisexual flowers are very poorly understood. In this study, the inflorescence and flower development of P. volubilis were investigated using light microscopy and scanning electron microscopy. We also investigated the effects of cytokinin on flower sex determination by exogenous application of 6-benzyladenine (BA) in P. volubilis. The floral development of P. volubilis was divided into eight stages, and the first morphological divergence between the male and female flowers was found to occur at stage 3. Both female and male flowers can be structurally distinguished by differences in the shape and size of the flower apex after sepal primordia initiation. There are no traces of gynoecia in male flowers or of androecia in female flowers. Exogenous application of BA effectively induced gynoecium primordia initiation and female flower development, especially at the early flower developmental stages. We propose that flower sex is determined earlier and probably occurs before flower initiation, either prior to or at inflorescence development due to the difference in the position of the female and male primordia in the inflorescence and in the time of the female and male primordia being initiated. The influence of cytokinin on female primordia during flower development in P. volubilis strongly suggests a feminization role for cytokinin in sex determination. These results indicate that cytokinin could modify the fate of the apical meristem of male flower and promote the formation of carpel primordia in P. volubilis.

Sex determination and Y chromosome constitutive heterochromatin

2019 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Abyt Ibraimov
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Constitutive Heterochromatin ◽  
Sex Differentiation ◽  
Secondary Sexual Characteristics ◽  
Biological Meaning ◽  
Heterochromatin Block ◽  
Sexual Characteristics ◽  
Open Question ◽  
Efficient Elimination

In many animals, including us, the genetic sex is determined at fertilization by sex chromosomes. Seemingly, the sex determination (SD) in human and animals is determined by the amount of constitutive heterochromatin on Y chromosome via cell thermoregulation. It is assumed the medulla and cortex tissue cells in the undifferentiated embryonic gonads (UEG) differ in vulnerability to the increase of the intracellular temperature. If the amount of the Y chromosome constitutive heterochromatin is enough for efficient elimination of heat difference between the nucleus and cytoplasm in rapidly growing UEG cells the medulla tissue survives. Otherwise it doomed to degeneration and a cortex tissue will remain in the UEG. Regardless of whether our assumption is true or not, it remains an open question why on Y chromosome there is a large constitutive heterochromatin block? What is its biological meaning? Does it relate to sex determination, sex differentiation and development of secondary sexual characteristics? If so, what is its mechanism: chemical or physical? There is no scientifically sound answer to these questions.

scholarly journals Identification of sex differentiation-related microRNA and long non-coding RNA in Takifugu rubripes gonads

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongwei Yan ◽  
Qi Liu ◽  
Jieming Jiang ◽  
Xufang Shen ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Sex Determination ◽  
High Throughput Sequencing ◽  
Sex Differentiation ◽  
Mature Mirnas ◽  
Takifugu Rubripes ◽  
Sequencing Technology ◽  
Non Coding Rna ◽  
Differentially Expressed Mirnas ◽  
Tiger Pufferfish ◽  
Long Non Coding Rna

AbstractAlthough sex determination and differentiation are key developmental processes in animals, the involvement of non-coding RNA in the regulation of this process is still not clarified. The tiger pufferfish (Takifugu rubripes) is one of the most economically important marine cultured species in Asia, but analyses of miRNA and long non-coding RNA (lncRNA) at early sex differentiation stages have not been conducted yet. In our study, high-throughput sequencing technology was used to sequence transcriptome libraries from undifferentiated gonads of T. rubripes. In total, 231 (107 conserved, and 124 novel) miRNAs were obtained, while 2774 (523 conserved, and 2251 novel) lncRNAs were identified. Of these, several miRNAs and lncRNAs were predicted to be the regulators of the expression of sex-related genes (including fru-miR-15b/foxl2, novel-167, novel-318, and novel-538/dmrt1, novel-548/amh, lnc_000338, lnc_000690, lnc_000370, XLOC_021951, and XR_965485.1/gsdf). Analysis of differentially expressed miRNAs and lncRNAs showed that three mature miRNAs up-regulated and five mature miRNAs were down-regulated in male gonads compared to female gonads, while 79 lncRNAs were up-regulated and 51 were down-regulated. These findings could highlight a group of interesting miRNAs and lncRNAs for future studies and may reveal new insights into the function of miRNAs and lncRNAs in sex determination and differentiation.

scholarly journals Molecular Cloning and Expression Analysis of a MADS-Box Gene (GbMADS2) from Ginkgo biloba

2015 ◽  
Vol 43 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Xiaohui WANG ◽  
Junhuan CHENG ◽  
Feng XU ◽  
Xingxiang LI ◽  
Weiwei ZHANG ◽  
...  
Keyword(s):  
Expression Analysis ◽  
Ginkgo Biloba ◽  
Flower Development ◽  
Time Course ◽  
Male Flower ◽  
Cloning And Expression ◽  
Pcr Analysis ◽  
Mads Box ◽  
Typical Structure ◽  
Mads Box Gene

As a kind of transcription factors gene family, MADS-box genes play an important role in plant development processes. To find genes involved in the floral transition of Ginkgo biloba, a MADS-box gene, designated as GbMADS2, was cloned from G. biloba based on EST sequences by RT-PCR. Sequence analysis results showed that the cDNA sequence of GbMADS2 contained a 663 bp length ORF encoding 221 amino acids protein, which displayed typical structure of plant MADS-box protein including MADS, I, and K domains and C terminus. The sequence of GbMADS2 protein was highly homologous to those of MADS-box proteins from other plant species with the highest homologous to AGAMOUS (CyAG) from Cycas revoluta. The phylogenetic tree analysis revealed that GbMADS2 belonged to AGAMOUS clade genes. Real-time PCR analysis indicated that expression levels of GbMADS2 gene in female and male flower were significantly higher than those in root, stem, and leaves, and that GbMADS2 expression level increased along with time of flower development. The spatial and time-course expression profile of GbMADS2 implied that GbMADS2 might be involved in development of reproductive organs. The isolation and expression analysis of GbMADS2 provided basis for further studying the molecular mechanism of flower development in G. biloba.

scholarly journals The genome and transcriptome of the Phalaenopsis yield insights into floral organ development and flowering regulation

2016 ◽  
Author(s):  
Jian-Zhi Huang ◽  
Chih-Peng Lin ◽  
Ting-Chi Cheng ◽  
Ya-Wen Huang ◽  
Yi-Jung Tsai ◽  
...  
Keyword(s):  
Economic Value ◽  
Draft Genome ◽  
Floral Organ ◽  
Cool Temperature ◽  
Organ Development ◽  
Nucleotide Polymorphisms ◽  
Protein Coding ◽  
Draft Genome Assembly ◽  
Genome Data ◽  
Expression Of Genes

Phalaenopsis orchid is an important potted flower with high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis ‘KHM190’ cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima ‘B8802’, a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal the key role of PhAGL6b in the regulation of flower organ development involves alternative splicing. We also show gibberellin pathways that regulate the expression of genes control flowering time during the stage in reproductive phase change induced by cool temperature. Our work should contribute a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids.

scholarly journals Sex differentiation in grayling (Salmonidae) goes through an all-male stage and is delayed in genetic males who instead grow faster

2017 ◽  
Author(s):  
Diane Maitre ◽  
Oliver M. Selmoni ◽  
Anshu Uppal ◽  
Lucas Marques da Cunha ◽  
Laetitia G. E. Wilkins ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Determination ◽  
Sex Differentiation ◽  
Sex Ratios ◽  
Molecular Genetic ◽  
Specific Gene ◽  
Genetic Sexing ◽  
Experimental Conditions ◽  
Two Samples

AbstractFish can be threatened by distorted sex ratios that arise during sex differentiation. It is therefore important to understand sex determination and differentiation, especially in river-dwelling fish that are often exposed to environmental factors that may interfere with sex differentiation. However, sex differentiation is not sufficiently understood in keystone taxa such as the Thymallinae, one of the three salmonid subfamilies. Here we study a wild grayling (Thymallus thymallus) population that suffers from distorted sex ratios. We found sex determination in the wild and in captivity to be genetic and linked to the sdY locus. We therefore studied sex-specific gene expression in embryos and early larvae that were bred and raised under different experimental conditions, and we studied gonadal morphology in five monthly samples taken after hatching. Significant sex-specific changes in gene expression (affecting about 25,000 genes) started around hatching. Gonads were still undifferentiated three weeks after hatching, but about half of the fish showed immature testes around seven weeks after hatching. Over the next few months, this phenotype was mostly replaced by the “testis-to-ovary” or “ovaries” phenotypes. The gonads of the remaining fish, i.e. approximately half of the fish in each sampling period, remained undifferentiated until six months after fertilization. Genetic sexing of the last two samples revealed that fish with undifferentiated gonads were all males, who, by that time, were on average larger than the genetic females (verified in 8-months old juveniles raised in another experiment). Only 12% of the genetic males showed testicular tissue six months after fertilization. We conclude that sex differentiation starts around hatching, goes through an all-male stage for both sexes (which represents a rare case of “undifferentiated” gonochoristic species that usually go through an all-female stage), and is delayed in males who, instead of developing their gonads, grow faster than females during these juvenile stages.Author contributionMRR and CW initiated the project. DM, OS, AU, LMC, LW, and CW sampled the adult fish, did the experimental in vitro fertilizations, and prepared the embryos for experimental rearing in the laboratory. All further manipulations on the embryos and the larvae were done by DM, OS, AU, LMC, and LW. The RNA-seq data were analyzed by OS, JR, and MRR, the histological analyses were done by DM, supervised by SK, and the molecular genetic sexing was performed by DM, OS, AU, and KBM. DM, OS, and CW performed the remaining statistical analyses and wrote the first version of the manuscript that was then critically revised by all other authors.

scholarly journals Spliceosomal Protein Gene BmSPX Regulates Reproductive Organ Development in Bombyx mori

2020 ◽  
Vol 21 (7) ◽  
pp. 2579
Author(s):  
Yao Wang ◽  
Juan Li ◽  
Qiu-Xing Wan ◽  
Qin Zhao ◽  
Kai-Xuan Wang ◽  
...  
Keyword(s):  
Sex Determination ◽  
Bombyx Mori ◽  
Protein Gene ◽  
External Genitalia ◽  
Reproductive Organs ◽  
Reproductive Organ ◽  
Organ Development ◽  
Regulatory Factor ◽  
Transgenic Silkworm ◽  
Spliceosomal Protein

Sex determination and differentiation are nearly universal to all eukaryotic organisms, encompassing diverse systems and mechanisms. Here, we identified a spliceosomal protein gene BmSPX involved in sex determination of the lepidopeteran insect, Bombyx mori. In a transgenic silkworm line that overexpressed the BmSPX gene, transgenic silkworm males exhibited differences in their external genitalia compared to wild-type males, but normal internal genitalia. Additionally, transgenic silkworm females exhibited a developmental disorder of the reproductive organs. Upregulation of BmSPX significantly increased the expression levels of sex-determining genes (BmMasc and BmIMP) and reduced the female-type splice isoform of Bmdsx, which is a key switch gene downstream of the sex-determination pathway. Additionally, co-immunoprecipitation assays confirmed an interaction between the BmSPX protein and BmPSI, an upstream regulatory factor of Bmdsx. Quantitative real-time PCR showed that BmSPX over-expression upregulated the expression of the Hox gene abdominal-B (Adb-B), which is required for specification of the posterior abdomen, external genitalia, and gonads of insects, as well as the genes in the Receptor Tyrosine Kinase (RTK) signaling pathway. In conclusion, our study suggested the involvement of BmSPX, identified as a novel regulatory factor, in the sex-determination pathway and regulation of reproductive organ development in silkworms.

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