Scholarly Literature
This is a database of scholarly literature that concentrates currently on natural and engineered selfish genetic elements (gene drives). The latest are shown here.
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Meiotic drive in natural populations of Drosophila melanogaster .4: Instability at the Segregation Distorter locus
4515Sandler, LH, Y., Genetics, 45:1269-1287. 1960-01-13 00:00:00.
In a collection of flies from a natural population of Drosophila melanogaster, several second chromosomes have been isolated that contain, in the centromere region .of chromosome 11, a locus (named segregation-distorter and symbolized SO) that conditions, in heterozygous males, a highly abnormal segregation ratio in favor of the SD-bearing chromosome. Experiments bearing on the cytogenetic basis of the phenomenon of segregation-distortion and on the formal genetics of the SD locus have been reported by SANDLER, HIRAIZUMI, and SANDLER (1959). and by SANDLER and HIRAIZUMI ( 1959).
Meiotic drive in natural populations of Drosophila melanogaster .5. On the nature of the SD region
4514Sandler, LH, Y., Genetics, 45:1671-1689. 1960-01-12 00:00:00.
Second chromosomes were collected from nature which, when heterozygous with a normal chromosome 1 in males, are present in functional sperm much more often than the expected 50 percent. This phenomenon, named segregation distortion, was found to depend on a locus named Segregation-distorter (symbolized SD), which is located near the centromere (and probably in the right arm) of chromosome 1
Meiotic drive in natural-populations of Drosophila melanogaster 3: Populational implications of the Segregation-Distorter locus
4513Hiraizumi, YS, L.; Crow, J. E., Evolution, 14:433-444. 1960-01-11 00:00:00.
If, among the successful gametes frm heterozygotes, one allele is regularly included in more than half, it may increase in frequency even if it has a harmful effect. Unequal gamete production, when attributable to the mechanics of meiosis, has been called meiotic drive (Sandler and Novitski, 1957). An example is segregation-distortion in Drosophila melanogaster, the cytogenetic behavior of which has been reported by Sander, Hiraizumi and Sandler (1959) and Sandler and Hiraizumi (1959)
Meiotic drive in natural populations of Drosophila melanogaster .1. The cytogenetic basis of segregation distortion
4517Sandler, LH, Y.; Sandler, I., Genetics, 44:233-250. 1959-01-15 00:00:00.
Meiotic drive has been defined as a force, potentially capable of altering gene frequencies in natural populations, which somehow depends upon the nature of the meiotic divisions; specifically, when the meiotic divisions are such that the two kinds of gametes from a heterozygote are produced in a ratio different from 1 : 1 ( SANDLER and NOVITSKI 195 7). There have been reported numerous cases which either are, or may be, examples of meiotic drive. These include cases in Drosophila ( GERSHENSON 1928; STURTEVANT and DOBZHANSKY 1936; NOVITSKI 1951 ; NOVITSKI and IRIS SANDLER 1957; LINDSLEY and SANDLER 1958), in maize (RHOADES 1942; LONGLEY 1945), in tobacco (CAMERON and MOAV 1957), and possibly in mice (DUNN 1953) and in man (DUNN 1953; SANDLER and NOVITSKI 1957). The purpose of this paper is to present a first account of the results of a series of studies designed to elucidate the cytogenetic basis of a case of meiotic drive which was discovered in a natural population of D. melanogaster. In this population there has been found a second chromosome locus, located in or near the proximal heterochromatin and called segregation-distorter (symbol, SO), which is recovered much more frequently than its normal allele among the progeny of heterozygous male parents. This phenomenon, to which the name segregation distortion has been applied, (1) has never been found to occur in females, (2) apparently requires synapsis (particularly in the region of the locus in question) in order to operate, and (3) comes about as a result of the failure of sperm carrying the normal allele to be formed or to function normally. The evidence bearing on these, and certain other points, and a cytogenetic model to account for the results are presented below.
Meiotic drive in natural populations of Drosophila melanogaster 2. Genetic variation at the Segregation Distorter locus
4516Sandler, LH, Y., Proceedings of the National Academy of Sciences of the United States of America, 45:1412-1422. 1959-01-14 00:00:00.
It has now been found that the proportion of heterozygous SD males resulting from any given cross which exhibits segregation-distortion, and the amount of distortion that any particular male shows (the k value), varies widely depending upon the precise source and history of the SD-bearing and the SD+-bearing chromosomes in the heterozygotes being tested. It is the purpose of this report to present a general account of the kinds of variations in the behavior of SD which have been observed. More fully documented reports of each phase of the work are currently in preparation, and will be presented elsewhere. For this reason, extended discussion of these variations and comparable systems in other organisms has been omitted.
Possible replacement of malaria mosquitoes
6118S. Avery Jones, Transactions of The Royal Society of Tropical Medicine and Hygiene, 51:469-470. 1957-08-10 19:43:41.
Sir,--The purpose of this letter is to draw the attention of research workers in control of mosquito colonies to the possible value of investigating the factors governing the infection of mosquitoes with parasites of human malaria. If a strain of a vector species could be isolated that has inability to become infective as a dominant characteristic, the way would be opened up to implant such mosquitoes in areas where the normal vectors of the same species have been reduced in numbers. There is the hope that they would breed and become locally predominant.
Meiotic drive as an evolutionary force
4518Sandler, L. and Novitski, E., American Naturalist, 91:105-110. 1957-01-16 00:00:00.
A heterozygote for alleles A and A' ordinarilly produces gametes carrying each of the alleles with a frequency of 50 per cent. The constancy of allele frequencies from one generation to the nest in natural populations of diploid species depends on this equality, which itself depends on the nature of the meiotic divisions. As the study of the genetics of higher organisms becomes more precise and extensive, an increasing number of cases is found in which heterozygotes of certain constitutions fail to produce the two kinds of gametes with equal frequency. Such a pattern of behavior will drastically alter frequencies of alleles in a population; where such a fouce, potentially capable of altering gene frequencies, is a consequence of the mechanics of the meiotic divisions, we suggest that the name meiotic drive be applied. The distinction between meiotic drive and the superficially similar phenomenon of gametic selection and gametic competition may be operationally difficult in those instances in which a detailed cytogenetic study cannot be made. The later, however, represent selecdtion in the ordinary sense, operating in the haploid phase, and as such their effectiveness is directly dependent on the gene content (fitness) of the gametes, whereas the effectiveness of the former is independent of the gene content in the ordinary sense.
Inheritance in Nicotiana tabacum XXVII. Pollen Killer, An alien genetic locus inducing abortion of microspores not carrying it
6116D. R. Cameron and R. M. Moav, Genetics, 42:326. 1957-01-02 19:37:02.
A cytogenetic study of experimental introgression from N. plumbaginifolia (pbg) into N. tabacum (tbc) has been pursued in this laboratory for several years (CLAUSEN 1952). In the hybrid derivatives it was observed that genically controlled pollen abortion was associated with the addition of a pbg chromosome to the tbc complement. This chromosome also carried the locus (Bs) determining resistance or probably immunity to black shank, a serious disease of commercial tobacco caused by Phytophthora parasitica var. nicotianae. (For description see CLAYTON and AICAIVRTRY 1950). Paradoxically, it developed that the pbg chromosome under study produced its effect on gametophytes in which it was not present. Thus, the male gametophytes containing a complete set of 24 tbc chromosomes degenerate while most of the functional pollen had the constitution 24 tbc + 1 pbg. This paper presents a description of the genetic aspects of the problem with some suggestions as to the possible method of action of the locus involved. Certain other phases of the larger investigation will be mentioned but only as they apply to the pollen lethal condition. The investigation was initiated by the late PROF. R. E. CLAUSEN who participated actively in the work presented here.
Studies of the genetic variability in populations of wild house mice .2. Analysis of eight additional alleles at locus – T
6113L. C. Dunn, Genetics, 42:299-311. 1957-01-02 19:27:44.
1 Eight additional lethal alleles at locus T are described, each derived from a wild heterozygote in one of six different wild populations. 2. The frequency of heterozygotes appears to be high in most wild populations, possibly as high as 50 percent. 3. In two of the populations in which several heterozygotes were found, the same allele was isolated from each heterozygote of the same population. One heterozygote was found in each of two subpopulations on the same farm. These two alleles have not been shown to be different. One wild heterozygote from another population transmitted two different alleles; probably one was a new mutant, giving rise to the possibility that more than one allele may occur in the same population, although the rule at present is to find but one type of variant allele per population. 4. All wild t alleles show the “male segregation ratio peculiarity” by which male heterozygotes transmit the t allele to a great majority (about 96 percent) of the offspring. This may be due to the effects of natural selection on factors favoring high transmission ratios. 5. t alleles from the wild fall into at least three groups, one with three viable alleles, and two groups of lethals. Lethals within the same group have not formed viable compounds when combined; lethals belonging to different groups do form viable compounds by complementary interaction and are thus shown to be nonidentical. 6. Since 29 alleles have now been detected at this locus, many of which are nonidentical, the locus is assumed to contain many sites of mutation and to have great potential complexity.
Screw-worm control through release of sterilized flies
6107A. H. Baumhover, A. J. Graham, B. A. Bitter, D. E. Hopkins, W. D. New, F. H. Dudley and R. C. Bushland, Journal of Economic Entomology, 48:462-466. 1955-08-03 17:00:44.
Screw-worms, Callitroga hominivorax (Cqrl.), did not exist in the southeastern United States until about 20 years ago, and it is probable that, if the present infestation could be eradicated, the area might be kept free of infestation through inspection of livestock shipments originating in infested areas
Possibilities of Insect Control or Eradication Through the Use of Sexually Sterile Males
6006E. F. Knipling, Journal of Economic Entomology, 48:459-462. 1955-08-01 19:58:21.
The purpose of this paper is to consider the possibility of controlling insects by releasing sexually sterile males among the existing natural population. The principles involved will be described and the potentialities as well as the limitations of the method as we know them at present, will be discussed.
Eradication of screw-worms through release of sterilized males
6091R. C. Bushland, A. W. Lindquist and E. F. Knipling, Science, 122:287-288. 1955-01-02 14:50:36.
Although the sterilizing effect of ionizing radiations has been known for years, it is only recently that entomologists have attempted to take advantage of the phenomenon for insect control. Knipling (1) has theorized on the effects of releasing sterilized males among a normal insect population. In 1947, on a visit to the Kerrville, Tex., laboratory, he proposed investigations on the mating habits of the screw-worm, Callitroga hominivorax (Cqrl.), and experiments with sterilized males. In such experiments Bushland and Hopkins (2) found that screw-worms were easily sterilized by exposing pupae to x-rays or gamma rays. They showed that under laboratory conditions male screw-worms mated repeatedly but fe males only once. If a female mated with a sterilized male it did not mate again and laid eggs that did not hatch. When mixed populations of normal and sterilized insects were observed in cages, the sterilized and normal males competed about equally for mates.
Mutable loci in maize.
6388B. McClintock, Carnegie Inst. Washington Year Book, 47:155-169. 1948-02-10 16:25:33.
Previous reports have state that the number of unstable loci have recently arisen in maize culture. In a particular cell of a plant, a normal "wild-type" locus becomes altered; the normal, dominant expression of this locus changes and gives rise to a recessive expression (or, in several cases, a recessive locus become unstable and mutates toward a dominant expression). This expression of the locus need not be permanent. In some decendent cells, a second change may occur within the locus that results in the restoring of the capacity of thelocus to express the dominant phenotype or brings about an intermediate expression between full recessive and full dominant. In the latter case, a third alteration may occur in some decendent cells that steps up the phenotype expression toward the full dominant or reduces it toward the full recessive.
Experiments in the hybridisation of tsetse-flies (Glossina, Diptera) and the possibility of a new method of control.
6139F. L. Vanderplank, Transactions of the Royal Entomological Society of London, 98:1-18. 1947-01-02 21:38:18.
Hybridisation of Glossina morsitans Westwood, G. swynnertoni Austen and G. pallidipes Austen was attempted in order to discover(a) Whether the three could be regarded as distinct species or as sub-species of morsitans ; (b) Whether they would mate freely with one another, and if not by what means the three closely allied forms distinguished their own kind ; (c) Whether morsitans and swynnertoni would readily produce hybrid offspring, and if so, what proportion of females would do so, and what proportion of hybrids would be sterile ; (d) Finally, whether interference with one species by another could be used as a measure of control. I also wanted to explore other details including markings, colouration and nature of the genitalia of the hybrids, and whether these characters were constant or variable.
Parasitic nature of extra fragment chromosomes
6003Östergren G., Botaniska Notiser, 2:157-163. 1945-12-30 19:52:12.
This paper is intended as a contribution to the discussion concerning the significance of the extra fragments or »accessory chromosomes» as they are called by Håk ansso n(1945), which are not too rarely found in cross-fertilizing populations. I think reasonable support may he given to the view that in many cases these chromosomes have no useful function at all to the species carrying them, but that they often lead an exclusively parasitic existence.
Tsetse hybrids
6145W. H. Potts, Nature, 154:606-607. 1944-11-11 21:48:03.
IN 1936 I attempted to cross various species of tsetse (Glossina) with the idea that, should they hybridize readily, and should the resultant hybrids prove sterile, this might be tried as a measure of control. Corson had already, in 1932, obtained three offspring from crosses between male G. swynnertoni and female G. morsitans; he suggested, however, that these might not be true hybrids, but the result of parthenogenesis (see further details in the accompanying communication by Mr. F. L. Vanderplank). I obtained a number of offspring from this and other crosses, but as a slight doubt arose as to whether they were authentic hybrids, the results were never published.
Hybridization between Glossina Species and Suggested New Method for Control of Certain Species of Tsetse
6142F. L. Vanderplank, Nature, 154:607-608. 1944-11-11 21:43:25.
Corson and Potts record crossing Glossina swynnertoni Aust. with G. morsitans Westwood. Corson crossed twelve female G. morsitans with male G. swynnertoni, of which only two females produced a total of three pupæ. All his females lived long enough for reproduction to take place. He records the offspring, all females, as being identical with pure-bred G. morsitans, and suggested parthenogenesis. Potts crossed both male G. morsitans with female G. swynnertoni and male G. swynnertoni with female G. morsitans (see accompanying communication by Mr. W. H. Potts).
Preferential segregation in maize
6000M. M. Rhoades, Genetics, 27:395-407. 1942-12-30 19:47:18.
An abnormal type of chromosome 10, found by Longley in maize from the s.-w. part of the U. S., is preferentially segregated during megasporogenesis. More than 70% of the ovules receive the abnormal chromosome instead of the 50% expected with random segregation. At pachytene the length of the extra piece of chromatin in the abnormal chromosome is slightly greater than the short arm of chromosome 10. The proximal and distal portions of the extra piece are euchromatic, but a large and conspicuous knob lies between the 2 euchromatic portions. The origin of this extra piece is unknown. Pollen with the abnormal chromosome 10 is only partially successful in competing with pollen possessing a normal chromosome 10. Extra chromatin present in the abnormal chromosome may impair pollen-tube growth. The excess of ovules with the abnormal type of chromosome is due neither to abortion of ovules with a normal chromosome nor to megaspore competition. The R locus, known to lie in the long arm of chromosome 10, proved to be closely linked to the extra piece of chromatin which is believed to be inserted near the tip of the long arm. The observed % of recombination (1-2%) is probably less than the amt. occurring distal to R in stocks carrying 2 normal chromosomes 10. Crossing-over in the gR region is not affected when the abnormal chromosome is heterozygous, and crossing-over in this interval did not affect preferential segregation. Evidence was obtained indicating the influence of the environment on the degree of preferential segregation.
On the possibility of a new method for the control of insect pests.
6157A. S. Serebrovskii, Zoologicheskiĭ zhurnal, 19:618-630 (in Russian). 1940-01-03 16:43:28.
ON THE POSSIBILITY OF A NEW METHOD FOR THE CONTROL OF INSECT PESTS. The new principle of insect control consists in disturbing the propagation of the pest population by means of translocations. It is well known that individuals heterozygous for some translocations usually form a portion of aneuploid gametes and give a more or less inviable aneuploid progeny. On releasing, therefore, a sufficient number of individuals with a chromosome set altered by. translocations into a wild population (with allogamous propagation), there will arise heterozygotes for translocations yielding a certain percentage of inviable offspring. Crosses inside this population will be similar to those between species with resulting sterility of hybrids. The theoretical analysis reveals that if a wild population is mixed in proportion 1:1 with some race containing only one translocation viable in homozygous condition and giving in heterozygotes 50% of aneuploid gametes, the reproduction of the population will be reduced by 43%. If several races with different allelic translocations are released the reduction of reproduction in the population can reach 75%, and if races with 4-5 independent translocations are used the reduction can attain 95%-99% and even more. A population consisting of races with different translocations cannot remain in balance. Those types of chromosomes which happened to be in minority are subjected to elimination. Yet this process of elimination will go on during many generations and thus the disturbance of reproduction will be protracted. By an additional releasing of eliminating race, this disturbance can be maintained permanently. Diverse variants of this method are possible, depending upon the biology and economic importance of injurious insects, the cost of breeding translocated races in laboratories, the difficulties of obtaining viable translocations, etc. It is possible, for instance, to release only males, a method in which there is evidently no danger at all. The present investigation is a purely theoretical one. For the purpose of verifying experimentally this idea work has been started with Musca domestica and Calandra granaria - two insects widely differing in their cytogenetics, ecology and the kind of damage caused.
A new sex-ratio abnormality in Drosophila obscura
6047S. Gershenson, Genetics, 13:488. 1928-12-30 21:32:10.
1. The sex-ratio in the normal lines of Drosophila obscura is very near to the theoretical 1 : 1. 2. Out of 19 females caught in nature, two were heterozygous for a gene which causes strong deviations in the normal sex distribution. 3. The researches made have shown that this gene is localized in the X-chromosome and is transmitted like an ordinary sex-linked gene. 4. This gene is absolutely sex-limited, as it is not manifested either in heterozygous or homozygous females. 5. The males bearing this gene give in their progeny about 96 percent of females and only about 4 percent of males. 6. This gene has no influence on the development of the zygotes already formed, but acts directly upon the mechanism of sex-distribution. It provokes a sharp preponderance of females by almost totally removing the spermatozoa with the Y-chromosome from the fertilization process, acting thus like a gametic lethal (in the genetic sense of this term).
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