scholarly journals The ethylene receptors CpETR1A and CpETR2B cooperate in the control of sex determination in Cucurbita pepo

2019 ◽  
Vol 71 (1) ◽  
pp. 154-167 ◽  
Author(s):  
Alicia García ◽  
Encarnación Aguado ◽  
Cecilia Martínez ◽  
Damian Loska ◽  
Sergi Beltrán ◽  
...  
Keyword(s):  
Growth Rate ◽  
Sex Determination ◽  
High Throughput Screening ◽  
Cucurbita Pepo ◽  
Missense Mutations ◽  
Coding Region ◽  
Ethylene Receptors ◽  
Time Required ◽  
Sex Determination Mechanisms ◽  
Ethylene Insensitivity

Abstract High-throughput screening of an ethyl methanesulfonate-generated mutant collection of Cucurbita pepo using the ethylene triple-response test resulted in the identification of two semi-dominant ethylene-insensitive mutants: etr1a and etr2b. Both mutations altered sex determination mechanisms, promoting conversion of female into bisexual or hermaphrodite flowers, and monoecy into andromonoecy, thereby delaying the transition to female flowering and reducing the number of pistillate flowers per plant. The mutations also altered the growth rate and maturity of petals and carpels in pistillate flowers, lengthening the time required for flowers to reach anthesis, as well as stimulating the growth rate of ovaries and the parthenocarpic development of fruits. Whole-genome sequencing allowed identification of the causal mutation of the phenotypes as two missense mutations in the coding region of CpETR1A and CpETR2B, each one corresponding to one of the duplicates of ethylene receptor genes highly homologous to Arabidopsis ETR1 and ETR2. The phenotypes of homozygous and heterozygous single- and double-mutant plants indicated that the two ethylene receptors cooperate in the control of the ethylene response. The level of ethylene insensitivity, which was determined by the strength of each mutant allele and the dose of wild-type and mutant etr1a and etr2b alleles, correlated with the degree of phenotypic changes in the mutants.

scholarly journals Love is in the air: ethylene and sex determination in Cucurbita pepo

2019 ◽  
Vol 71 (1) ◽  
pp. 4-6
Author(s):  
Susanne Schilling ◽  
Paul F McCabe ◽  
Rainer Melzer
Keyword(s):  
Sex Determination ◽  
Cucurbita Pepo ◽  
Ethylene Receptors ◽  
Experimental Botany

This article comments on: García A, Aguado E, Martínez C, Loska D, Beltrán S, Valenzuela JL, Garrido D, Jamilena M. 2019. The ethylene receptors CpETR1A and CpETR2B cooperate in the control of sex determination in Cucurbita pepo. Journal of Experimental Botany 70, 154–167.

scholarly journals Field study suggests that sex determination in sea lamprey is directly influenced by larval growth rate

2017 ◽  
Vol 284 (1851) ◽  
pp. 20170262 ◽  
Author(s):  
Nicholas S. Johnson ◽  
William D. Swink ◽  
Travis O. Brenden
Keyword(s):  
Growth Rate ◽  
Sex Determination ◽  
Sex Ratios ◽  
Petromyzon Marinus ◽  
Larval Growth ◽  
Sea Lamprey ◽  
Growth Conditions ◽  
Larval Growth Rate ◽  
Sex Determination Mechanisms ◽  
Insight Into

Sex determination mechanisms in fishes lie along a genetic-environmental continuum and thereby offer opportunities to understand how physiology and environment interact to determine sex. Mechanisms and ecological consequences of sex determination in fishes are primarily garnered from teleosts, with little investigation into basal fishes. We tagged and released larval sea lamprey ( Petromyzon marinus ) into unproductive lake and productive stream environments. Sex ratios produced from these environments were quantified by recapturing tagged individuals as adults. Sex ratios from unproductive and productive environments were initially similar. However, sex ratios soon diverged, with unproductive environments becoming increasingly male-skewed and productive environments becoming less male-skewed with time. We hypothesize that slower growth in unproductive environments contributed to the sex ratio differences by directly influencing sex determination. To the best of our knowledge, this is the first study suggesting that growth rate in a fish species directly influences sex determination; other studies have suggested that the environmental variables to which sex determination is sensitive (e.g. density, temperature) act as cues for favourable or unfavourable growth conditions. Understanding mechanisms of sex determination in lampreys may provide unique insight into the underlying principles of sex determination in other vertebrates and provide innovative approaches for their management where valued and invasive.

Environmental Sex Determination Mechanisms in Reptiles

2013 ◽  
Vol 7 (1-3) ◽  
pp. 95-103 ◽  
Author(s):  
H. Merchant-Larios ◽  
V. Díaz-Hernández
Keyword(s):  
Sex Determination ◽  
Environmental Sex Determination ◽  
Sex Determination Mechanisms

scholarly journals RNAi-Mediated Gene Silencing in a Gonad Organ Culture to Study Sex Determination Mechanisms in Sea Turtle

Genes ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. 293-305 ◽  
Author(s):  
Itzel Sifuentes-Romero ◽  
Horacio Merchant-Larios ◽  
Sarah Milton ◽  
Norma Moreno-Mendoza ◽  
Verónica Díaz-Hernández ◽  
...  
Keyword(s):  
Organ Culture ◽  
Gene Silencing ◽  
Sex Determination ◽  
Sea Turtle ◽  
Sex Determination Mechanisms

The Effect of Temperature on the Growth and Respiration of Fish Embryos (Salmo Fario)

1932 ◽  
Vol 9 (3) ◽  
pp. 271-276
Author(s):  
A. H. WOOD
Keyword(s):  
Growth Rate ◽  
Oxygen Consumption ◽  
Relative Intensity ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Effect Of Temperature ◽  
Total Oxygen ◽  
Average Efficiency ◽  
Complete Development ◽  
Time Required

1. The rate of respiration (as expressed in c.c. O2 per gram embryo per hour) of the embryos of Salmo fario remains constant at any given temperature until the embryo has reached its maximum growth-rate, after this point it declines. It is suggested that the rate of respiration may be proportional to the amount of available yolk. 2. When incubated at 7° C. the time required to complete development after hatching was 58 days and the total oxygen consumed by an average embryo during this period was 20·31 c.c. (N.T.P.). At 12° the time required for the completion of development was reduced to 27 days, but the oxygen consumption remained practically unchanged at 20·71 c.c. At 3° C. the time required for development was 108 days and the oxygen consumption was 26·96 c.c. per embryo. 3. At 7 and 12° C. the efficiency of development was found to be identical with the value given by Gray for 11·5° C., viz. 63 per cent.; at 3°C. the average efficiency over the period considered was only 54 per cent. 4. It is suggested that, between the limits of temperature to which a trout egg is normally exposed, the effect of temperature on respiration is neither greater nor less than its effect on the growth-rate; possibly both processes are dependent on the same controlling factor. Above and below this range of temperature, the relative intensity of the respiratory processes (to those of growth) is increased, and a smaller embryo is the final result of incubation.

scholarly journals Double heterozygosity for mutations in the platelet glycoprotein IX gene in three siblings with Bernard-Soulier syndrome

Blood ◽  
1993 ◽  
Vol 81 (9) ◽  
pp. 2339-2347 ◽  
Author(s):  
SD Wright ◽  
K Michaelides ◽  
DJ Johnson ◽  
NC West ◽  
EG Tuddenham
Keyword(s):  
Normal Subjects ◽  
Immunoblot Analysis ◽  
Platelet Glycoprotein ◽  
Bleeding Tendency ◽  
Missense Mutations ◽  
Coding Region ◽  
Giant Platelets ◽  
Double Heterozygosity ◽  
Induced Aggregation ◽  
Bernard Soulier Syndrome

Abstract Bernard-Soulier syndrome (BSS) giant platelets have defective and/or deficient glycoprotein (GP) Ib/IX complexes, causing absent ristocetin- induced aggregation, defective interaction with von Willebrand factor, morphologic abnormality, and a clinical bleeding tendency. Recently several mutations have been described in the platelet GPIb alpha gene in individuals exhibiting the BSS phenotype. We have studied a family with classical BSS, and have excluded lesions at the GPIb alpha locus by restriction fragment length polymorphism linkage analysis. Analysis of the genes for two other components of the platelet GPIb:IX complex, namely GPIb beta and GPIX, showed two different missense mutations in the coding region of the GPIX gene: an A-->G transition in codon 21 results in conversion of an aspartic acid to glycine and an A-->G change in codon 45 converts an asparagine residue to serine. Three affected individuals are doubly heterozygous for these mutations, which alter conserved residues in or flanking the GPIX leucine-rich glycoprotein motif. Both mutations create new recognition sites for the enzyme Fnu 4H1; therefore, this enzyme was used to screen 60 normal subjects (120 alleles). Neither mutation was detected in any subject other than direct relatives of the affected individuals. Although low levels of GPIb were demonstrable by both flow cytometry and immunoblot analysis in an affected individual's platelets, there was no evidence of GPIX immunoreactivity. We propose that expression of abnormal GPIX prevents stable assembly of the GPIb/IX complex, causing BSS in the doubly heterozygous individuals in this family.

scholarly journals Identification of Bruton's tyrosine kinase (Btk) gene mutations and characterization of the derived proteins in 35 X-linked agammaglobulinemia families: a nationwide study of Btk deficiency in Japan

Blood ◽  
1996 ◽  
Vol 88 (2) ◽  
pp. 561-573 ◽  
Author(s):  
S Hashimoto ◽  
S Tsukada ◽  
M Matsushita ◽  
T Miyawaki ◽  
Y Niida ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
B Cell ◽  
Kinase Activity ◽  
Protein Analysis ◽  
Kinase Assay ◽  
Bruton’S Tyrosine Kinase ◽  
Missense Mutations ◽  
Coding Region ◽  
Bruton's Tyrosine Kinase ◽  
Nationwide Study

Deficiencies of Bruton's tyrosine kinase (Btk) have been implicated in the pathogenesis of human X-linked agammaglobulinemia (XLA). The distinctive phenotype observed in B-cell deficiency indicates the crucial role of Btk in B-cell development. This report describes a nationwide study of Btk deficiency in Japan, covering 51 XLA patients (35 independent families). Along with the identification of mutations, the resulting protein products were characterized by an in vitro kinase assay and a Western blot analysis. Thirty-one of the families were found to have mutations in the coding region of Btk. Although mutations were not found in the cDNA of 4 families, the Btk transcripts of these patients were greatly reduced. The identification of several novel missense mutations, in combination with the result of other studies, clarified the presence of two (missense) mutation hot spots, one in the SH1 and the other in the PH domain. The absence of kinase activity seen in 32 of the families underscored the importance of Btk protein analysis as a diagnostic indicator of XLA. The protein analysis also clarified the different effects of missense mutations on kinase activity and protein stability.

scholarly journals Analysis of the gene coding for steroidogenic factor 1 (SF1, NR5A1) in a cohort of 50 Egyptian patients with 46,XY disorders of sex development

2014 ◽  
Vol 170 (5) ◽  
pp. 759-767 ◽  
Author(s):  
Sally Tantawy ◽  
Inas Mazen ◽  
Hala Soliman ◽  
Ghada Anwar ◽  
Abeer Atef ◽  
...  
Keyword(s):  
Adrenal Insufficiency ◽  
Direct Sequencing ◽  
Disorders Of Sex Development ◽  
Missense Mutations ◽  
Coding Region ◽  
Steroidogenic Factor 1 ◽  
Sex Development ◽  
Gene Coding ◽  
Future Fertility

ObjectiveSteroidogenic factor 1 (SF1, NR5A1) is a key transcriptional regulator of genes involved in the hypothalamic–pituitary–gonadal axis. Recently, SF1 mutations were found to be a frequent cause of 46,XY disorders of sex development (DSD) in humans. We investigate the frequency of NR5A1 mutations in an Egyptian cohort of XY DSD.DesignClinical assessment, endocrine evaluation and genetic analysis of 50 Egyptian XY DSD patients (without adrenal insufficiency) with a wide phenotypic spectrum.MethodsMolecular analysis of NR5A1 gene by direct sequencing followed by in vitro functional analysis of the two novel missense mutations detected.ResultsThree novel heterozygous mutations of the coding region in patients with hypospadias were detected. p.Glu121AlafsX25 results in severely truncated protein, p.Arg62Cys lies in DNA-binding zinc finger, whereas p.Ala154Thr lies in the hinge region of SF1 protein. Transactivation assays using reporter constructs carrying promoters of anti-Müllerian hormone (AMH), CYP11A1 and TESCO core enhancer of Sox9 showed that p.Ala154Thr and p.Arg62Cys mutations result in aberrant biological activity of NR5A1. A total of 17 patients (34%) harboured the p.Gly146Ala polymorphism.ConclusionWe identified two novel NR5A1 mutations showing impaired function in 23 Egyptian XY DSD patients with hypospadias (8.5%). This is the first study searching for NR5A1 mutations in oriental patients from the Middle East and Arab region with XY DSD and no adrenal insufficiency, revealing a frequency similar to that in European patients (6.5–15%). We recommend screening of NR5A1 in patients with hypospadias and gonadal dysgenesis. Yearly follow-ups of gonadal function and early cryoconservation of sperms should be performed in XY DSD patients with NR5A1 mutations given the risk of future fertility problems due to early gonadal failure.

scholarly journals Application of QuantiGene™ Nucleic Acid Quantification Technology for High Throughput Screening

2000 ◽  
Vol 5 (5) ◽  
pp. 343-351 ◽  
Author(s):  
Usha Warrior ◽  
Yihong Fan ◽  
Caroline A. David ◽  
Julie A. Wilkins ◽  
Evelyn M. McKeegan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
High Throughput ◽  
High Throughput Screening ◽  
Molecular Probes ◽  
Epithelial Cell Line ◽  
Reporter System ◽  
Screening Assay ◽  
Human Lung Epithelial Cell ◽  
High Throughput Screening Assay ◽  
Time Required

To identify inhibitors of interleukin-8 (IL-8) production, a high throughput assay was developed using the Quanti-Gene™ nucleic acid quantification kit that employs branched-chain DNA (bDNA) technology to measure the mRNA directly from cells. Unlike polymerase chain reaction and other technologies that employ target amplification, the QuantiGene system uses signal amplification. To perform the assay, various molecular probes capable of hybridizing with IL-8 mRNA were designed and synthesized. A human lung epithelial cell line was treated with interleukin-la (IL-la) to stimulate the IL-8 gene expression and the mRNA was measured using the QuantiGene system. The QuantiGene assay was sensitive, flexible, and reproducible and achieved equivalent or better sensitivity than promoter-reporter assays, and eliminated the time required for constructing a promoter-reporter system. Our data show that bDNA technology has the potential to be used as a high throughput screening assay.

Sign in / Sign up

Export Citation Format

Share Document