SD-72 has a temperature-sensitive period during spermiogenesis

1983 ◽  
Vol 25 (6) ◽  
pp. 662-667 ◽  
Author(s):  
Kathleen Matthews ◽  
Mark A. Mortin
Keyword(s):  
Drosophila Melanogaster ◽  
High Temperature ◽  
Segregation Distortion ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Proximate Cause ◽  
Naturally Occurring ◽  
Segregation Distorter

Segregation distorter (SD) chromosomes in Drosophila melanogaster are naturally occurring second chromosomes which produce greatly altered transmission frequencies when present in heterozygous males (Hartl and Hiraizumi 1976). The proximate cause of segregation distortion is abortion of spermatids carrying the non-SD homologue (Tokuyasu et al. 1977). SD-72, a chromosome previously shown (Mange 1968) to be unaffected by high temperature treatment of spermatocytes, a stage when several SD genotypes are temperature sensitive, has a temperature-sensitive period during spermiogenesis. SD-72/cn bw males exposed to a 24-h pulse of 29 °C, then brooded for 24 h, experience a decrease in segregation distortion of approximately two-thirds. The timing of the reduction in distortion indicates that the temperature-sensitive period is postmeiotic.

scholarly journals Temperature sensitivity of negative segregation distortion in Drosophila melanogaster.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 831-841 ◽  
Author(s):  
Y Hiraizumi
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Segregation Distortion ◽  
Current Model ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Absolute Increase ◽  
Negative Segregation ◽  
Absolute Reduction ◽  
Radical Revision

Abstract Previous work has shown that the direction of segregation distortion in the SD (Segregation Distorter) system in Drosophila melanogaster can sometimes be reversed, but this was found only with rather weak distorters and the effect was not large. The present study reports large negative segregation distortion in a strong distorter, SD-72 chromosome. In the presence of a specific X chromosome, supp-X(SD), the proportion, k, of SD-72 chromosomes recovered from the SD-72/cn bw males ranges from 0.99 at 20 degrees to 0.11 at 28.5 degrees, whereas with a standard-X chromosome, k ranges from 0.99 to 0.95 for the same temperature range. The temperature-sensitive period is during spermiogenesis. Using a mating system in which the sperm supply is nearly exhausted, it was shown that the negative distortion at high temperatures is due to an absolute reduction in the number of SD-72 chromosomes and an absolute increase in the number of cn bw chromosomes recovered. After adjusting for non-SD-related temperature effects, the amount of decrease in the number of SD-72 progeny is nearly the same as the amount of increase in the number of cn bw progeny, suggesting that the dysfunction switches from a spermatid carrying one homolog to one carrying the other. Negative distortion requires a radical revision of current hypotheses for the mechanism of segregation distortion and a possible modification of the current model is suggested, based on differential recovery of dysfunction in the two homologs during spermiogenesis.

scholarly journals ON THE COMPONENTS OF SEGREGATION DISTORTION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1977 ◽  
Vol 86 (2) ◽  
pp. 321-355
Author(s):  
Barry Ganetzky
Keyword(s):  
Drosophila Melanogaster ◽  
Segregation Distortion ◽  
Meiotic Drive ◽  
Chromosome 2 ◽  
Induced Mutations ◽  
Distorted Segregation ◽  
X Ray ◽  
Naturally Occurring ◽  
Segregation Distorter

ABSTRACT The segregation distorter (SD) complex is a naturally occurring meiotic drive system with the property that males heterozygous for an SD-bearing chromosome 2 and an SD  +-bearing homolog transmit the SD-bearing chromosome almost exclusively. This distorted segregation is the consequence of an induced dysfunction of those sperm that receive the SD  + homolog. From previous studies, two loci have been implicated in this phenomenon: the Sd locus which is required to produce distortion, and the Responder (Rsp) locus that is the site at which Sd acts. There are two allelic alternatives of Rsp—sensitive (Rspsens) and insensitive (Rspins); a chromosome carrying Rspins is not distorted by SD. In the present study, the function and location of each of these elements was examined by a genetic and cytological characterization of X-ray-induced mutations at each locus. The results indicate the following: (1) the Rsp locus is located in the proximal heterochromatin of 2R; (2) a deletion for the Rsp locus renders a chromosome insensitive to distortion; (3) the Sd locus is located to the left of pr(2-54.5), in the region from 37D2-D7 to 38A6-B2 of the salivary chromosome map; (4) an SD chromosome deleted for Sd loses its ability to distort; (5) there is another important component of the SD system, E(SD), in or near the proximal heterochromatin of 2L, that behaves as a strong enhancer of distortion. The results of these studies allow a reinterpretation of results from earlier analyses of the SD system and serve to limit the possible mechanisms to account for segregation distortion.

scholarly journals THE MECHANISM OF A BROODING EFFECT ASSOCIATED WITH SEGREGATION DISTORTION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 619-631
Author(s):  
D L Hartl
Keyword(s):  
Drosophila Melanogaster ◽  
Segregation Distortion ◽  
Mature Sperm ◽  
Temperature Sensitive ◽  
Short Time

ABSTRACT The recovery of the SD chromosome from a heterozygous SD male increases with brood. This is independent of the age of the female, occurs during the time the sperm are stored in the females, disappears when the segregation distortion is suppressed, and is temperature-sensitive-temperature shocks above or below 25°C applied to the mature sperm both tend to accelerate the increase in the recovery of SD. All this suggests the existence of a class of sperm affected by SD in which the sperm are able to fertilize eggs for a short time following ejaculation but become dysfunctional thereafter.

An experimental study on the fracture behaviors of marble specimens subjected to high temperature treatment

2020 ◽  
Vol 225 ◽  
pp. 106862 ◽  
Author(s):  
Qingzhen Guo ◽  
Haijian Su ◽  
Jiawei Liu ◽  
Qian Yin ◽  
Hongwen Jing ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Temperature ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Fracture Behaviors
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