Cytogenetical studies in Rhoeo spathacea (Commelinaceae). I. A desynaptic and second division restitution mutant

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 895-899 ◽  
Author(s):  
Armando Garcia-Velazquez

A mutant causing partial desynapsis (dissociation of paired chromosomes), and consequently a high frequency of univalents at metaphase 1, was found in Rhoeo spathacea among the selfed progeny of a wild-collected ring-forming complex interchange heterozygote. All the plants were diploid, 2n = 2x = 12. The mutant formed univalents in all microsporocytes (range 2–12; average 7.56/cell), and 23.69% of the pollen mother cells contained the maximum of 12 univalents at metaphase I. There was no significant difference in pollen fertility between the mutant and parental plants. The desynaptic mutant produced microspores with chromosome numbers of n = 6–14 in the same anther. Unreduced pollen was formed at telophase II by second division restitution and comprised 52.74% of the pollen grains. By selfing, diplandrogynous tetraploid progeny (2n = 4x = 24) of 12 seedlings were obtained. The results demonstrate that both male and female gametes are unreduced.Key words: Rhoeo, desynapsis, univalent, second division restitution, tetraploid.

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.


2017 ◽  
Vol 8 (2) ◽  
pp. 178-195
Author(s):  
Nurma Risa

This study aims to prove that there is a difference of perception about ethics on tax evasion in UNISMA Bekasi students, based on selected study program and gender. The sample of this research is the students who have fulfilled the subject of taxation, at the Faculty of Economics (FE) and Faculty of Social and Political Sciences (FISIP). Using independent t-test, the results showed that there was no significant difference of perception about tax evasion ethics between FE and FISIP students. But significant differences the perception of tax evasion ethics occur between accounting and management students at FE. Significant differences also did not occur between male and female students


Author(s):  
Nisha Chandel ◽  
Seema Chopra

The present study was undertaken to find out emotional intelligence and academic achievement of male and female adolescents. The sample consists of 82 students( 41 male and 41 female adolescents) from different schools in Hamirpur district of Himachal Pradesh. Emotional intelligence was assessed with the help of Emotional Intelligence Scale developed by Singh and Narain (2014) and academic achievement score were taken from the school records. The results revealed that there exists a significant difference in emotional intelligence of male and female adolescents. It was found that there existed significant difference in academic achievement of female adolescents and male adolescents. The mean emotional intelligence of female adolescents was better than of male adolescents. On the dimensions of emotional intelligence, it was found that there was no significant difference between male and female adolescents on understanding emotions, empathy and handling relations dimensions of emotional intelligence; while it was reported that there was significant difference between male and female adolescents on understanding motivation dimension of emotional intelligence On the other hand, it was found that there existed significant difference in academic achievement of female adolescents and male adolescents.


Author(s):  
Kun Liu ◽  
Xueyan Yang ◽  
Moye Xin

Repetitive nonsuicidal self-injury (R-NSSI) is an extreme manifestation of nonsuicidal self-injury (NSSI) behavior that causes bodily harm and emotional and personality disorders. It is a growing concern, especially among adolescents; therefore, this study aims to provide empirical support for effective interventions on R-NSSI behavior among adolescents in China. We used data of about 1180 students from a survey conducted in seven middle schools in Xi’an, China, and applied multiple logistic regression to analyze NSSI and R-NSSI among male and female students, including their influencing factors. We found no significant difference between male and female students’ R-NSSI; however, regarding influencing factors, male students had more violent experiences and less social support than female students. Parental and familial factors played the most prominent role in social support. Social support was found to be a main-effect mechanism in the effect of violent experiences on R-NSSI among male students, whereas the mechanism had both a main effect and a certain buffer effect among female students. R-NSSI was found to be more prevalent among younger children, children with siblings, and those with romantic relationship experiences. We also found that healthy adolescent development involves the participation of families and schools. Health education should be conducted according to the students’ sex and characteristics.


Author(s):  
Max I. Phukan ◽  
Rohit K. Thapa ◽  
Gopal Kumar ◽  
Chris Bishop ◽  
Helmi Chaabene ◽  
...  

This study aimed to examine inter-limb jump asymmetries and their association with sport-specific performance in young swimmers. Thirty-eight (male, n = 19; female, n = 19) regional/national level young swimmers (age: 12.3 ± 1.2 years; height: 159.6 ± 8.2 cm; body mass: 52.5 ± 9.2 kg) participated in this study. Inter-limb asymmetries were assessed for single-leg countermovement jump (SLCMJ) and single-leg standing long jump (SLSLJ). Sport-specific performance was evaluated using front crawl (i.e., 50 m and 25 m) and front crawl kick (i.e., 50 m and 25 m). The kappa coefficient revealed a “slight” level of agreement (Κ = 0.156, 0.184, and 0.197 for female, male, and all, respectively) between the direction of asymmetry for SLCMJ and SLSLJ, indicating that asymmetries rarely favored the same limb during both tests. A paired sample t-test showed a significant difference (p = 0.025) between asymmetry scores obtained in SLCMJ and SLSLJ. No significant difference was found in asymmetry scores between males and females (p = 0.099 to 0.977). Additionally, no association between asymmetry scores and sport-specific performance was observed (p > 0.05). Our findings highlight the independent nature of inter-limb asymmetries derived from SLCMJ and SLSLJ among young male and female swimmers. Further, our results suggest no association between jumping asymmetries and sport-specific performance.


The Nucleus ◽  
2021 ◽  
Author(s):  
Fajarudin Ahmad ◽  
Yuyu S. Poerba ◽  
Gert H. J. Kema ◽  
Hans de Jong

AbstractBreeding of banana is hampered by its genetic complexity, structural chromosome rearrangements and different ploidy levels. Various scientific disciplines, including cytogenetics, linkage mapping, and bioinformatics, are helpful tools in characterising cultivars and wild relatives used in crossing programs. Chromosome analysis still plays a pivotal role in studying hybrid sterility and structural and numerical variants. In this study, we describe the optimisation of the chromosome spreading protocol of pollen mother cells focusing on the effects of standard fixation methods, duration of the pectolytic enzyme treatment and advantages of fluorescence microscopy of DAPI stained cell spreads. We demonstrate the benefits of this protocol on meiotic features of five wild diploid Musa acuminata bananas and a diploid (AA) cultivar banana “Rejang”, with particular attention on pairing configurations and chromosome transmission that may be indicative for translocations and inversions. Pollen slides demonstrate regular-shaped spores except “Rejang”, which shows fertile pollen grains of different size and sterile pollen grains, suggesting partial sterility and unreduced gamete formation that likely resulted from restitutional meiotic divisions.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Jayakrishna Tippabathani ◽  
Jayshree Nellore ◽  
Vaishnavie Radhakrishnan ◽  
Somashree Banik ◽  
Sonia Kapoor

Here, we study the expression of NURR1 and FOXA1 mRNA in peripheral blood lymphocytes and its haplotypes in coding region in a small Chennai population of India. Thirty cases of Parkinson’s patients (PD) with anti-PD medications (20 males aged65.85±1.19and 10 females aged65.7±1.202) and 30 age matched healthy people (20 males aged68.45±1.282and 10 females aged65.8±1.133) were included. The expression of NURR1 and FOXA1 in PBL was detected by Q-PCR and haplotypes were identified by PCR-SSCP. In the 30 PD cases examined, NURR1 and FOXA1 expression was significantly reduced in both male and female PD patients. However, NURR1 (57.631% reduced in males; 28.93% in females) and FOXA1 (64.42% in males; 55.76% in females) mRNA expression did differ greatly between male and female PD patients. Polymorphisms were identified at exon 4 of the NURR1 and at exon 3 of the FOXA1, respectively, in both male and female patients. A near significant difference in SSCP patterns between genders of control and PD population was analyzed suggesting that further investigations of more patients, more molecular markers, and coding regions should be performed. Such studies could potentially reveal peripheral molecular marker of early PD and different significance to the respective genders.


1988 ◽  
Vol 120 (4) ◽  
pp. 297-305 ◽  
Author(s):  
W. A. Charnetski

AbstractThree methods—tube chambers (ventilated and unventilated), petri dish chambers, and field cages—were used to evaluate the toxicity of deltamethrin, trichlorfon, and methoxychlor deposits on alfalfa, Medicago sativa L., to 1- to 7-day-old alfalfa leafcutter bees, Megachile rotundata (F.), 24 and 48 h after exposure. In unventilated tube chambers, all three insecticides were significantly toxic to male bees after 24 and 48 h, but only deltamethrin and trichlorfon were significantly toxic to female bees after 24 h. In ventilated tube chambers, only deltamethrin was significantly toxic by contact and then only to male bees at 24 h. Significant vapor action was observed only for trichlorfon and only in unventilated tube chambers. By the petri dish method, only deltamethrin caused significant mortality to male and female bees. However, bee mortality increased significantly between 24 and 48 h. By the field cage method, there was no significant difference in mortality among treatments and controls within the 24- and 48-h evaluations. Bee mortality in the controls was much higher in the petri dish and field cage methods than in either of the two variations of the tube chamber method. The three evaluation methods are compared and the need for a standardized laboratory evaluation procedure is discussed.


Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Joanna E. Werner ◽  
David S. Douches ◽  
Rosanna Freyre

The ratio of the first division restitution (FDR) to second division restitution (SDR) 2n eggs was estimated in 4182t, a haploid (2n = 2x = 24) of Solanum tuberosum L. that produces 2n eggs by the two modes. The segregation of three genes previously mapped relative to their centromeres, Pgm-2 (2.0 cM), Mdh-1 (33.5 cM), and 6-Pgdh-3 (30.1 cM) was analyzed in the tetraploid offspring of a 2x × 4x cross. Based on the segregation of the Pgm-2 locus, 39.7% of the progeny originated from FDR 2n eggs and 60.3% from SDR. Segregation patterns of the two distal loci within the FDR-derived 4x subpopulation indicated that the gene–centromere recombination rate during megasporogenesis was significantly reduced for Mdh-1 when compared with a previous estimate during microsporogenesis. In the SDR-derived 4x subpopulation, the gene–centromere recombination rates for Mdh-1 and 6-Pgdh-3 were not significantly different from previous estimates. Tetraploid progeny generated from one 2x × 4x cross where the 2x parent produces 2n gametes by two modes can be used to make an unbiased comparison of the potential breeding value of FDR and SDR gametes.Key words: potato, megasporogenesis, first division restitution, second division restitution, isozyme.


1979 ◽  
Vol 21 (4) ◽  
pp. 525-530 ◽  
Author(s):  
Nicholi Vorsa ◽  
E. T. Bingham

Four diploid (2x) clones of alfalfa, Medicago sativa L., which produced good seed set when used as male parents in 4x-2x crosses were selected for study. The 2x clones descended from 2x haploids of cultivated 4x alfalfa. Fertility in the 4x-2x cross was due to the production of pollen with the unreduced chromosome number (2n pollen) from the 2x parent. The cytological mechanism of 2n pollen formation was found to be disorientation of spindles at metaphase II in up to 38% of the pollen mother cells. Thus, both n and 2n pollen were produced by all four diploids examined. Normal spindles at metaphase II were oriented such that they defined the poles of a tetrahedron and resulted in normal tetrads in a tetrahedral arrangement. Disoriented spindles were basically parallel to each other and resulted in formation of dyads and occasionally a triad. Dyads developed into two 2n pollen grains; triads developed into one 2n and two n pollen grains. Since both n and 2n pollen grains are produced by the diploids, they can be maintained as diploids or they can be used as male parents in crosses to tetraploids. The genetic constitution of 2n pollen resulting from parallel spindles is similar to that expected after first division restitution of meiosis and much of the heterozygosity of the diploid parent is conserved in the gametes. The 2n gamete mechanism has potential application in germplasm transfer and in maximizing heterozygosity in tetraploid hybrids.


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