SOMATIC CHROMOSOMES OF HIGHER DIPTERA: VI. ALLOSOME–AUTOSOME LENGTH RELATIONS IN MUSCA DOMESTICA L.

1962 ◽  
Vol 40 (5) ◽  
pp. 777-784 ◽  
Author(s):  
J. W. Boyes ◽  
A. F. Naylor

The length of the two heterochromatic X-chromosomes of pair I in Musca domestica L. is compared with the total length of the five autosomal pairs in 50 mitotic chromosome complements of varying length in cells without colchicine or other pretreatment before fixation. Pair I is the longest pair in short complements and shifts gradually to become one of the shortest in long complements. The heterochromatic Y-chromosome is regularly the smallest chromosome but closely resembles the X in respect to this shifting length relationship. Arm ratios did not change with complement length. The great importance of providing actual total complement lengths with idiograms is emphasized.

2021 ◽  
Vol 29 (2) ◽  
pp. 100-107
Author(s):  
Serdar Yedier ◽  
Derya Bostanci ◽  
Nazmi Polat

Abstract The aim of the current study was to determine the length-weight relationship (LWR) and length-length relationship (LLR) with condition factor (K) values for Oxynoemacheilus angorae from the Perşembe Plateau meandering streams in Ordu, Turkey. A total of 65 fish specimens, which were caught with electrofishing gear, were examined. Fish standard length (SL), fork length (FL), total length (TL), and body weight (W) were determined. There were no statistical differences between the measurements of male and female O. angorae specimens; therefore, the female and male specimens were evaluated together in the current study. The LWR equation and determination coefficient of O. angorae were W = 0.014 TL2.7359 (r2 = 0.9659). The 95% confidence interval of the b value for the O. angorae specimens from the Perşembe Plateau meandering streams was 2.7261 to 2.7435. In the present study, it was determined that O. angorae specimens showed negative allometric growth. Calculations of O. angorae TL-SL, TL-FL, and FL-SL relationship equations and determination coefficients were as follows: TL = 0.2091+1.1646 SL, (r2 = 0.986); TL = 0.1341+1.0301 FL (r2 = 0.9914); and FL = 0.0998+1.1261 SL, (r2 = 0.9868), respectively. A new maximum total length was recorded for O. angorae in this study. The average condition factor value of O. angorae was 0.9954. This value could have indicated that this species was encountering some problems in this habitat. The O. angorae parameters determined were the first data reported for the Perşembe Plateau meandering streams in Ordu, Turkey (Middle Black Sea Region).


2016 ◽  
pp. 5189-5197
Author(s):  
Charles W Olaya-Nieto ◽  
Liquey Camargo-Herrera ◽  
Vanessa Díaz-Sajonero ◽  
Fredys F Segura-Guevara

ABSTRACTObjective. The feeding habits of Cocobolo (Andinoacara pulcher) in the cienaga Grande de Lorica, Sinu river basin, were studied. Materials and methods. The stomach content was analyzed using the Proportion of empty stomachs, Grade of digestion, Frequency of occurrence, numerical Frequency, Gravimetry, relative importance Index (RII) and the gut length-total length relationship. Results. 39.8% of stomachs were empty, 47.1% of preys were fresh and five food groups were identified. Vegetable remains was the most frequent group (63.8%) and the prey with greatest composition in weight (33.5%), while Rest of fishes was the most abundant group (34.7%). It was observed that in low and rising waters, fishes was the most consumed prey, while that in high and falling waters the most consumed prey was vegetable remains. Vegetable remains, detritus and fishes were food groups of secondary relative importance, while Insects and Others were circumstantial or incidental groups. Conclusions. The results achieved indicate that Cocobolo is a fish with omnivores feeding habits with a preference for fishes and vegetable remains. RESUMEN Objetivo. Se estudiaron los hábitos alimentarios de Cocobolo (Andinoacara pulcher) en la ciénaga Grande de Lorica, cuenca del río Sinú, Colombia. Materiales y Métodos. El contenido estomacal se evaluó con el Coeficiente de vacuidad, Grado de llenado, Grado de digestión, Frecuencia de ocurrencia, Frecuencia numérica, Gravimetría, Índice de importancia relativa y la relación longitud intestinal- longitud total. Resultados. El 39.8% de los estómagos se encontró vacío, el 47.1% de las presas en estado fresco y se identificaron cinco grupos alimentarios. Material vegetal fue el grupo más frecuente (63.8%) y con mayor composición por peso (33.5%), mientras que Restos de peces fue el más abundante (34.7%). Se observó que en aguas bajas y en aguas ascendentes, peces fue la presa más consumida, mientras que en aguas altas y aguas descendentes, fue material vegetal. Material vegetal, detritos y restos de peces fueron grupos alimentarios de importancia relativa secundaria, mientras que insectos y otros fueron circunstanciales o incidentales. Conclusiones. Los resultados alcanzados indican que Cocobolo es un pez de hábitos alimentarios omnívoros con preferencia por peces y material vegetal.


Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 3-4
Author(s):  
Anne McLaren

In the first two papers of this volume, the genetic control of sex determination in Caenorhabditis and Drosophila is reviewed by Hodgkin and by Nöthiger & Steinmarin-Zwicky, respectively. Sex determination in both cases depends on the ratio of X chromosomes to autosomes, which acts as a signal to a cascade of règulatory genes located either on autosomes or on the X chromosome. The state of activity of the last gene in the sequence determines phenotypic sex. In the third paper, Erickson & Tres describe the structure of the mouse Y chromosome and the polymorphisms that have been detected in different mouse species and strains. As in all mammals, the Y carries the primary male-determining locus; autosomal genes may also be involved in sex determination, but they must act down-stream from the Y-linked locus.


2015 ◽  
Vol 26 ◽  
pp. 10-14
Author(s):  
Bharat Raj Subba ◽  
Satya Narayan Mehta ◽  
Shaligram Adhikaree

Present paper attempts to describe length-weight (LW) and total length-standard length (TL and SL) relationships of fresh-water garfi sh Xenentodon cancila. Fish of different length and weight were caught using cast nets from Muriyadhar, Sunsari. The fish were kept in ice box in fresh condition and brought to fi sh laboratory, Department of Zoolog post Graduate Campus, Biratnagar. The data obtained from measurement were analysed using the formula W = aLb. The b values estimated for the total length and standard length in relation to body weight were 3.2202 and 3.2559 respectively. The values of b clearly indicate the allometric growth pattern and for total length and standard length relationship, the linear value of b was 0.3223.J. Nat. Hist. Mus. Vol. 26, 2012: 10-14


2020 ◽  
Vol 12 (558) ◽  
pp. eaaz5677 ◽  
Author(s):  
Emily J. Davis ◽  
Lauren Broestl ◽  
Samira Abdulai-Saiku ◽  
Kurtresha Worden ◽  
Luke W. Bonham ◽  
...  

A major sex difference in Alzheimer’s disease (AD) is that men with the disease die earlier than do women. In aging and preclinical AD, men also show more cognitive deficits. Here, we show that the X chromosome affects AD-related vulnerability in mice expressing the human amyloid precursor protein (hAPP), a model of AD. XY-hAPP mice genetically modified to develop testicles or ovaries showed worse mortality and deficits than did XX-hAPP mice with either gonad, indicating a sex chromosome effect. To dissect whether the absence of a second X chromosome or the presence of a Y chromosome conferred a disadvantage on male mice, we varied sex chromosome dosage. With or without a Y chromosome, hAPP mice with one X chromosome showed worse mortality and deficits than did those with two X chromosomes. Thus, adding a second X chromosome conferred resilience to XY males and XO females. In addition, the Y chromosome, its sex-determining region Y gene (Sry), or testicular development modified mortality in hAPP mice with one X chromosome such that XY males with testicles survived longer than did XY or XO females with ovaries. Furthermore, a second X chromosome conferred resilience potentially through the candidate gene Kdm6a, which does not undergo X-linked inactivation. In humans, genetic variation in KDM6A was linked to higher brain expression and associated with less cognitive decline in aging and preclinical AD, suggesting its relevance to human brain health. Our study suggests a potential role for sex chromosomes in modulating disease vulnerability related to AD.


1970 ◽  
Vol 12 (3) ◽  
pp. 461-473 ◽  
Author(s):  
K. Y. Jan ◽  
J. W. Boyes

The karyotype of Musca domestica L. ocra strain, consists of the sex chromosomes and five autosomal pairs. The heteromorphic sex chromosomes are heterochromatic and mitotically unpaired, whereas the autosomes are euchromatic and mitotically paired. All autosomal pairs and both X and Y chromosomes are cytologically recognizable.The relative labelling rate, R (in terms of the number of grains counted per 100 labelled metaphases per μ of chromosome length) for the sex chromosomes and for each autosomal pair was followed from 1.5 hours to 8 hours after H3TdR injection. The pattern of labelling rate was similar for the different autosomal pairs in the XX cells but this pattern for the autosomal pairs in the XY cells, though also similar for the different pairs, differed appreciably from that found in the XX cells. The pattern of the labelling rate for the X chromosomes was similar in the XX and XY cells. Also the pattern of labelling rate for the X and Y chromosomes was similar during the final part of the replication period. The two X chromosomes in the XX cells and the X and Y chromosomes in the XY cells completed labelling later than the autosomes.


2020 ◽  
Vol 147 ◽  
pp. 02011
Author(s):  
Selvia Oktaviyani ◽  
Wanwan Kurniawan ◽  
Fahmi

Shark fins are a very valuable product for international trade. This study aims to obtain the equations describing the relationship between fin length and the total length of silky shark. Using the total length at sexual maturity (Lm), the equation is then used to estimate the fin length associated with this Lm, which can then be included in the recommendation for international shark fin trades. Data collection was carried out from March 2018 to February 2019 at Tanjung Luar Fish Landing Port, West Nusa Tenggara. All data were collected from 2,837 individuals of silky sharks, consisting of 1,416 females and 1,421 males. The total length of silky shark ranges from 61 to 282 cm for females and 18-283 cm for males. The relationships of first dorsal fin length and total length is DFL=2.0151+0.1243 TL (both sexes). Furthermore, the relationships of pectoral fin length and total length were found to be PFL=-8.0098+0.2127 TL (both sexes). The first dorsal fin length and pectoral fin length at the time the silky shark sexually matures were 23 cm and 35 cm, respectively. This fin-total length relationship can be used by the fisheries authority to determine the allowed minimum size of silky shark fins for export.


1993 ◽  
Vol 71 (10) ◽  
pp. 1963-1972 ◽  
Author(s):  
R. H. Gooding

When genetically marked Glossina morsitans submorsitans Newstead were mated to Glossina morsitans centralis Machado, viable offspring were obtained when using G. m. submorsitans females but not when using G. m. centralis females. The maternally inherited sterility factor, from G. m. submorsitans, that causes this asymmetry was inactivated or replaced during recurrent backcrossing to G. m. centralis. F1 hybrid males were sterile but most F1 hybrid females were fertile. There was little evidence for differential transmission of G. m. submorsitans and G. m. centralis chromosomes by hybrid females. Almost all backcross males were sterile if they had an X and a Y chromosome from two different taxa; the exceptional males had recombinant X chromosomes. The X chromosome locus for X/Y compatibility lies closer to the locus for esterase-X than to the locus for glucose-6-phosphate dehydrogenase. Heterozygosity in linkage group II is also a factor in causing hybrid male sterility; the locus for compatibility is closer to the locus for octanol dehydrogenase than to the locus for esterase-1. Among the backcross males that had an X and a Y chromosome from the same taxon, 12% of those obtained by backcrossing to G. m. centralis were fertile and 65% of those obtained by backcrossing to G. m. submorsitans were fertile. Backcrossing F1 hybrid females to G. m. submorsitans produced females that were equally likely to be fertilized by G. m. submorsitans and G. m. centralis. However, backcrossing to G. m. centralis produced females that had a much lower probability of being fertilized by G. m. submorsitans than by G. m. centralis.


1977 ◽  
Vol 55 (10) ◽  
pp. 1759-1762 ◽  
Author(s):  
K. L. Ying ◽  
D. G. Peden

Karyotypes of wood bison (Bison bison athabascae) and plains bison (Bison bison bison) were studied. Both subspecies were characterized by the same number of chromosomes (2n = 60), acrocentric autosomes, submetacentric X chromosomes, and an acrocentric Y chromosome. G-banding patterns suggest that when comparing wood bison and plains bison, 20 pair plus the sex chromosomes are homologous. Whether or not the remaining nine pair of chromosomes are homologous remains unknown.


2004 ◽  
Vol 64 (3b) ◽  
pp. 677-682 ◽  
Author(s):  
M. J. T. Ranzani-Paiva ◽  
A. T. Silva-Souza

This study involved 334 specimens of mullet, Mugil platanus, captured monthly in the estuarine region of Cananéia, São Paulo State, Brazil, from July 1988 to June 1989, and examined for the presence of gill parasites. Parasitological inspections revealed the occurrence of the following groups: Trichodina sp., Monogenoidea, Copepoda, and Hirudinea. Only four mullets were not parasitized. Total weight and total length of all 334 mullet specimens examined were used for adjusting the weight-length relationship curve and calculating the relative condition factor (Kn). The 118 specimens infested with monogenoideans on average had lower weights than expected (Kn < 1.0), and the 81 fish co-infested with Copepoda, Monogenoidea, and Trichodina sp. showed a Kn < 1.0. The other infested and non-infested mullets had a Kn > 1.0. It was possible to infer that gill infestation with monogenoideans alters mullet weight, especially in the presence of co-infestation with Trichodina sp. and copepods.


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