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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Experimental population-genetics of meiotic drive systems .1: Pseudo-Y chromosomal drive as a means of eliminating cage populations of Drosophila melanogaster

4487
Lyttle, TW,  Genetics,  86:413-445. 1977-01-05 00:00:00.
The experimental population genetics of Y-chromosome drive in Drosophila; melanogasier is approximated by studying the behavior of T(Y;S),SD lines.; These exhibit “pseudo-Y” drive through the effective coupling of the Y chromosome; to the second chromosome meiotic drive locus, Segregation distorter; (SD). T(Y;S),SD males consequently produce only male offspring. When; such lines are allowed to compete against structurally normal SD+ flies in; population cages, T(Y;S),SD males increase in frequency according to the; dynamics of a simple haploid selection model until the cage population is; eliminated as a result of a deficiency in the number of adult females. Cage; population extinction generally occurs within about seven generatiomSeveral; conclusions can be drawn from these competition cage studies:; (1) Fitness estimates for the T(Y;Z),SD lines (relative to SD+) are generally; in the range of 2-4, and these values are corroborated by; independent estimates derived from studies of migration-selection; equilibrium.; (2) Fitness estimates are unaffected by cage replication, sample time, or; the starting frequency of T(Y;Z),SD males, indicating that data from; diverse cages can be legitimately pooled to give an overall fitness; estimate.; (3) Partitioning of the T(Y;S),SD fitnesses into components of viability,; fertility, and frequency of alternate segregation (Y + SD from; X+SD+) suggests that most of the T(Y;S),SD advantage derives; from the latter two components. Improvements in the system might; involve increasing both the viability and the alternate segregation to; increase the total fitness.; While pseudo-Y drive operates quite effectively against laboratory stocks,; it is less successful in eliminating wild-type populations which are already; segregating for suppressors of SD action. This observation suggests that further

Field trial of competitive displacement of Aedes-polynesiensis by Aedes-albopictus on a Pacific atoll

6235
L. Rosen, L. E. Rozeboom, W. C. Reeves, J. Saugrain and D. J. Gubler,  American Journal of Tropical Medicine and Hygiene,  25:906-913. 1976-11-01 21:53:54.
Prior laboratory studies and field observations suggested that it might be possible to reduce the size of the population of, or eliminate, Aedes polynesiensis by the introduction of Aedes albopictus. The former mosquito is the principal vector of nonperiodic filariasis caused by Wuchereria bancrofti and the latter is a closely related species refractory to the development of human filariae. The practicability of such competitive displacement was studied by a field trial on a remote coral atoll where there was an established population of A. polynesiensis. Three strains of A. albopictus were liberated at separate localities on the atoll and their fate was followed for 4 years. One strain disappeared within 12 months after release and the other two disappeared within 48 months. It was not clear whether A. albopictus failed to become established because the strains were unsuitable, the general environment was inappropriate, or A. polynesiensis was present in such numbers that A. albopictus rarely succeeded in mating with its own species.

Between family variation in sex-ratio in Trinidad (T-30) strain of Aedes-aegypti (L) indicating differences in sensitivity to meiotic drive gene MD

4494
Wood, RJ,  Genetica,  46:345-361. 1976-01-12 00:00:00.
Sex ratio in the Trinidad (T-30) strain of Aedes aegypti has remained constant at around 43%? during seventeen years of laboratory culture. The divergence from 50% is due to meiotic drive by the MD gene on the Y chromosome. The driving Y chromosome gives a much more distorted sex ratio (mean = 5.7%?) when coupled with the highly sensitive X chromosomes from strain 64. This was demonstrated in all of 98 families tested, indicating that all or most of the Y chromosomes in T-30 carry the MD gene. Consequently the low level of sex ratio distortion in T-30 must be due to resistance to MD.; ; Crosses made within T-30 demonstrated wide differences in sex ratio between families, depending on the sensitivity of the male parent's X chromosome to MD. However, sex ratios were not continuously variable but fell within fairly discrete categories. Thus, X chromosomes could be classified according to the modal sex ratios associated with them: ms3 (12.5%?), ms2 (32.5%?), ms1 (40%?), mr1 (47.5%?) mr2 (57.5%?).; ; The different sex ratio categories were more discrete in the families of sib matings than from random matings, suggesting the possibility of background modification of what is essentially a balanced polymorphism. Evidence is presented suggesting that the polymorphism could be due to interaction at two loci. A further X variant, ms4 (<10%?) characterised strain 64 but was absent from T-30.; ; A comparison of fertility between the different sex ratio categories in T-30 established that sex ratio distortion was not caused by differential mortality after fertilisation.

Population genetics of modifiers of meiotic drive.3. Equilibrium analysis of a gneral model for genetic control of segregation distortion

4493
Thomson, GJF, M. W.,  Theoretical Population Biology,  10:8-25. 1976-01-11 00:00:00.
Prout, Bungaard and Bryant (1973, Theor. Popul. Biol. 4, 446–465) presented the first formal treatment of a model of meiotic drive involving a modifier locus which controls the intensity of drive. They studied the equilibrium behavior in the simplest model where it is assumed that drive is maximal when not suppressed. In that case there is one polymorphic equilibrium at which there is linkage disequilibrium. The equilibrium solutions in the general model of meiotic drive proposed by Prout, et al. are given in this paper together with a stability analysis. It is shown that up to three polymorphic equilibria may exist, two of which are in linkage disequilibrium and one in linkage equilibrium. These equilibria exhibit behavior qualitatively opposite to what is widely accepted as the usual for two locus systems and which is not seem in the simple case originally treated. The polymorphic equilibria with linkage disequilibrium may be stable for loose linkage and not for tight while that with linkage equilibrium is stable in an interval of relatively tight linkage values.

Evidence for autosomal meiotic drive in the butterfly Danaus chrysippus L.

4492
Smith, DAS,  Heredity,  36:139-142. 1976-01-10 00:00:00.
Danaus chrysippus (Danaidae) in East Africa is highly polymorphic for colour, the genetic control of which resides at three loci. The B locus has two alleles, B giving a nutbrown ground colour and bb orange on both fore and hindwings. The C locus determines forewing pattern: there are two alleles, C giving a wing uniformly coloured except for a black margin (form dorippus) and cc a large black apical area traversed by a row of white subapical spots (form ae&yptius = form chrysippus of my earlier papers). Heterozygotes (Cc) are basically dorippus but are often phenotypically distinct in showing the "aegyptius" subapical spots on the underside of the forewing. The B and C loci are closely linked (Smith, 1975a). The A locus has a recessive allele a the homozygous possessor of which has a large white patch on the hindwing (form alcippus when combined with the aegyptius forewing and form albinus with the dorippus forewing). The A locus probably assorts independently from the B and C loci (Clarke, Sheppard and Smith, 1973; Smith, 1975a). All-female broods commonly occur in D. chrysippus. These probably result when a Y-linked gene D causes meiotic drive for the Y chromosome so that it always enters the secondary oocyte at the first meiotic division in the female. Females from all-female broods usually themselves produce allfemale broods but a switch to bisexual broods can occur and seems to depend on the acquisition of a dominant autosomal suppressor gene S from the maternal male grandparent. The S locus is probably closely linked with the C locus (Smith, 1975b).

Cytogenetic analysis of meiotic drive in mosquito, Aedes aegypti

4491
Newton, MEW, R. J.; Southern, D. I.,  Genetica,  46:297-318. 1976-01-09 00:00:00.
Meiotic drive in Aedes aegypti (L.) is shown by a Giemsa C-banding technique to be associated with. preferential isochromatid breakage of the X chromosome during male meiosis. These breaks remain open at least until anaphase-I and, since the range of cells affected is proportional to the sensitivity of the X chromosome to the Distorter gene, it is argued that they are directly related to the decreased number of spermatozoa found in distorting males. This reduction is considered to be attributable to the degeneration of more X- than Y-bearing spermatids but it is probable that some non-functional X-bearing spermatozoa are also produced. Chromosome breakage is almost completely confined to four sites, two adjacent to the centromere, one just proximal to the intercalary band and another about the centre of the unbanded arm. Although the first three of these lie within a region in which crossing-over does not take place, fragmentation occurs more frequently in a chiasmate arm than in one devoid of chromatid exchange.

Population replacement in Culex-fatigans by means of cytoplasmic incompatibility .2. Field cage experiments with overlapping generations

6276
C. F. Curtis,  Bulletin of the World Health Organization,  53:107-119. 1976-01-08 16:51:11.
Three experiments were carried out in field cages to test the principle of " transport" of a desirable gene or chromosome into a wild Culex fatigans population as a result of the sterility in cross-matings associated with cytoplasmic incompatibility. Cycling populations of Delhi origin were established in the cages and daily releases were made of the IS31B strain, which has Paris cytoplasm and carries a male-linked translocation. It was shown that, if sufficient releases were made to establish a majority of the Paris cytoplasmic type, complete replacement by this cytoplasmic type subsequently occurred. However, as a result of partial compatibility of males of the Delhi population with Paris females, " recombinant " males with Paris cytoplasm and no translocation were produced. In an experiment in which a continuous low rate of " immigration " of a strain of Delhi origin was simulated, a gradual increase of the Paris cytoplasm non-translocated type occurred, and renewed IS31B releases were necessary after 5 months to restore the predominance of this type. The results are compared with computer predictions and discussed in relation to the transport of genes for filaria refractoriness or chromosome translocations into wild populations.

Modifier theory of meiotic drive: Is Mendelial segregation stable

4490
Liberman, U,  Theoretical Population Biology,  10:127-132. 1976-01-08 00:00:00.
The evolutionary fate of rare modifiers, based on the modifier theory of meiotic drive, is studied in this paper. It is shown that a polymorphism based on Mendelian segregation is never stable for any recombination frequencies between 0 and 12, and that, for tight linkage between the main locus and the modifier locus, the modifier locus tends towards heterozygosity.

Meiotic drive for B-chromosomes in primary oocytes of Myrmeleotettix maculatus (Orthoptera-Acrididae)

4489
Hewitt, GM,  Chromosoma,  56:381-391. 1976-01-07 00:00:00.
Using a modified technique which allowed observation of chromosome orientation in the primary oocyte of grasshoppers at the onset of anaphase, it has been possible to establish that the B-chromosome is distributed preferentially on the egg side of the metaphase plate rather than the polar body side. The frequency of this preferential orientation matches very closely the level of preferential transmission determined from breeding experiments using individuals from the same population. The spindle is asymmetrical in the primary oocyte of this species, and a possible explanation of the meiotic drive is proposed as a result of the conical shape of nucleoplasm surrounding this spindle. The autosomal chiasma frequency of these females is generally lower than comparable males and is increased by the presence of B chromosomes; but the chiasma frequencies of the sexes respond differently to the addition of 1 and 2 B-chromosomes.

Population genetics of modifiers of meiotic drive 4: Evolution of sex-ratio distortion

4497
Thomson, GJF, M. W.,  Theoretical Population Biology,  8:202-211. 1975-01-15 00:00:00.
A model for the evolution of the sex-ratio meiotic drive system in Drosophila is proposed and analyzed. The model incorporates drive and altered fertility genetic modification The condition change in the sex-ratio of the modifying distortion overcome any relative of meiotic in the carriers of the modified sex-ratio chromosomes. that a sex-ratio modifying chromosome increase is that the relative fertility chromosome. When no fertility model predicts that any increase in distortion differences are involved, of the sex ratio will be favored. loss in carriers the

Sex-chromosome meiotic drive systems in Drosophila melanogaster .1: Abnormal spermatid development in males with a heterochromatin-deficient X-chromosome (sc4sc8)

4496
Peacock, WJM, G. L. G.; Goodchild, D. J.,  Genetics,  79:613-634. 1975-01-14 00:00:00.
The meiotic drive characteristics of the In(1)sc4Lsc8R/Y system have been examined by genetic analysis and by light and electron microscopy. sc4sc8/Y males show a direct correlation between nondisjunction frequency and meiotic drive. Temperature-shift experiments reveal that the temperature-sensitive period for nondisjunction is at meiosis, whereas that for meiotic drive has both meiotic and post-meiotic components. Cytological analyses in the light and electron microscopes reveal failures in spermiogenesis in the testes of sc4sc8 males. The extent of abnormal spermatid development increases as nondisjunction becomes more extreme.

Modifier theory of meiotic drive

4495
Hartl, DL,  Theoretical Population Biology,  7:168-174. 1975-01-13 00:00:00.
The evolutionary fate of rare modifiers of recessive lethal segregation distorters has been studied. Suppressors or partial suppressors will always increase in frequency. Enhancers will increase in frequency if linkage is sufficiently tight and be lost if linkage is sufficiently loose.

Sex-ration, meiotic drive, and group selectin in Drosophila pseudoobscura

4498
Policansky, D,  American Naturalist,  108:75-90. 1974-01-16 00:00:00.
Sex ratio (SR) is a widespread genetic condition of the X-chromosome in Drosophila species which causes males to produce progenies consisting almost entirely of females. Results of samples from natural populations of Drosophila pseudoobscura and results of some laboratory experiments indicate that SR males produce only about half as many sperm as normal (ST) males; because of this deficiency, SR males are able to fertilize only about half as many eggs as ST males. These results explain the observed equilibria of frequencies of SR in natural populations, and suggest that, at least in the case of D. pseudoobscura, male fertility may be partly limited by the number of sperm males can produce.

Population replacement in Culex fatigens by means of cytoplasmic incompatibility. Laboratory experiments with non-overlapping generations

6291
C. F. Curtis and T. Adak,  Bulletin of the World Health Organization,  51:249-255. 1974-01-08 19:45:42.
Bidirectional cytoplasmic incompatibility in the Culex pipiens complex appears to provide a mechanism for the replacement of a wild population by a strain refractory to filaria or a strain made partly sterile by a translocation. As a preliminary test of the feasibility of the replacement process, various ratios of strains with the cytoplasm of either Delhi or Paris, which are bidirectionally incompatible, were tested in laboratory cages. Where one strain was marked with the ruby-eye gene, this strain always declined in frequency in the next generation. In experiments in which the Paris strain was marked with a male-linked translocation complex, after 2-4 generations of breeding there was complete elimination of either the Paris or the Delhi type depending, as expected, on the relative frequencies of the two types with which the population began. In one experiment a type with Paris cytoplasm devoid of the translocation was found. This type increased in frequency in succeeding generations. The possible causes of origin of this type and its relevance to the practical use of the replacement principle are discussed.

Genetic control of insect populations: I. Cage studies of chromosome replacement by compound autosomes in Drosophila melanogaste

6297
M. Fitz-Earle, D. G. Holm and D. T. Suzuki,  Genetics,  74:461-475. 1973-07-08 19:53:27.
A genetic method for insect control was evaluated using the test organism, Drosophila melanogaster. The technique involved the displacement under a system of continuous reproduction, of standard strains by those carrying compound autosomes. The eradication of the replacements could subsequently be achieved through the use of temperature-sensitive lethal mutations.—While certain compound autosome strains failed to displace standards in population cages, even at the initial release ratio of 25:1, others were highly successful. Indeed, for some strains when the ratio of compounds to standards was as low as 9:1, the population rapidly went to fixation in favor of the compound line.—Hatchability was found to be an insufficient index of fitness to estimate the initial ratios of compounds to standards that would guarantee fixation of the former. Differences in other fitness components, such as development time, were detected that could seriously modify displacement, especially with continuous overlapping generations. The importance of examining the fitness of various compound lines and selecting the most competitive in cages, prior to field tests, cannot be overemphasized.

Lâchers de mâles stériles de Glossina tachinoides West. dans un gîte naturel de faible densité Bas-Logone, Cameroun

26657
D. Cuisance and J. Itard,  Revue d’élevage et de médecine vétérinaire des pays tropicaux,  26:405-422. 1973-04-01 06:33:32.
Des mâles adultes de G. tachinoides, élevés à Maisons-Alfort et irradiés entre 7 600 et 10 650 rads à Saclay (France), ont été expédiés chaque semaine par avion à N'Djamena (Tchad) entre février et juin 1973, pour être, après marquage, lâchés en plusieurs points d'un gîte naturel, sur les berges du Logone. Par suite d'une sécheresse exceptionnelle, la population de mouches sauvages dans ce gîte étant de faible densité, la proportion de mâles stériles lâchés a pu être élevée, le rapport mâles stériles/mâles sauvages étant, en moyenne, pendant toute la période des lâchers, de 2,8/I. La longévité moyenne des mâles stériles a été de 6,5 jours contre 8 jours pour les mâles sauvages. Les mâles stériles ont eu un comportement identique à celui des mâles sauvages. Bien qu'un autre gîte, qui servait de témoin, ait été fortement dégradé par l'homme et les animaux, ce qui n'a pas permis d'apprécier exactement l'effet des lâchers de mâles stériles dans le gîte d'expérience, on estime cependant qu'à partir de la mi-mars, la chute de densité de la population sauvage est en grande partie due à la présence des mâles stériles, ce qui semble confirmé par l'observation de femelles sauvages capturées dans les deux gîtes: 69 p. 100 des femelles capturées dans le gîte d'expérience n'ont eu aucune descendance au cours de trois semaines d'observation, alors que toutes les femelles du gîte témoin ont produit une pupe dans les huit jours suivant leur capture

Comportement de mâles stériles de Glossina tachinoides West. lâchés dans les conditions naturelles – environs de Fort-Lamy (Tchad). I. Transport, lâchers, rythme d’activité, action sur la population sauvage

26645
D. Cuisance and J. Itard,  Revue d'élevage et de médecine vétérinaire des pays tropicaux,  26:55-76. 1973-01-01 15:42:14.
Glossina tachinoides adult males, bred and irradiated with 15,500 rads in Maisons-Alfort (France) were dispatched by air-mail to Fort-Lamy (Chad) between February and May of 1972, in order to be released, after marking, in a natural area of Cameroon side of the Chari river. In this first part, the authors analyse the consequences of breeding-irradiation-transport-handling ” factors on sterile males behaviour and activity rhythm. The too small a quantity of sterile males is essentially the cause of the absence of any measurable effect on naturel population evolution.

Changing population structure through the use of compound chromosomes

6295
D. Childress,  Genetics,  72:183-186. 1972-09-08 19:50:49.
Theoretical calculations and population cage data are presented to illustrate the use of compound chromosomes to change the genetic structure of insect populations.

Chromosome rearrangements for the control of insect pests

6293
G. G. Foster, M. J. Whitten, T. Prout and R. Gill,  Science,  176:875-880. 1972-05-26 19:48:27.
Over several years some biologists have been interested in the possibilities of employing genetic techniques in the control of insect pests. One idea has been to introduce in the natural population genotypes which could subsequently facilitate control, or which might render the pest innocuous. An- other idea that followed from the success of the .'sterile male" technique was to release genotypes with chromosomal aberrations whose subsequent segregation would result in sterility effects damaging to the population. Whitten (I) suggested combining these two ideas in one operation: in its simplest form the desired genotype would be obtained by incorporating the required genes in a chromosomal translocation. This would then be released as a homozygote in excess of the intrinsic unstable equilibrium which would result from the semisterility of the translocation heterozygote. The translocation producing the desired genotype would then autonomously become fixed while the genotype at the same time would produce sterile progeny in the early stages of the process. Thus we have the concept of a genetic transporting mechanism and a desired genotype to be transported, with the additional benefit of a transport device that might itself have transient damaging effects.

Multiple meiotic drive systems in Drosophila melanogaster male

4499
Miklos, GLGY, A. F.; Peacock, W. J.,  Genetics,  72:105-115. 1972-01-17 00:00:00.
The behaviour of two "meiotic drive" systems, Segregation-Distorter (SD) and the sex chromosome sc4sc8 has been examined in the same meiocyte. It has been found that the two systems interact in a specific way. When the distorting effects of SD and sc4sc8 are against each other, there is no detectable interaction. Each system is apparently oblivious to the presence of the other, gametes being produced according to independence expectations. However when the affected chromosomes are at the same meiotic pole an interaction occurs; the survival probability of the gamete containing both distorted chromosomal products is increased, rather than being decreased by the combined action of two systems.

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