A gynandromorphic grasshopper produced by double fertilization

1968 ◽  
Vol 16 (1) ◽  
pp. 101 ◽  
Author(s):  
MJD White

An individual of the large grasshopper Valanga irregularis (Walker) which exhibited bilateral gynandromorphism, is described. The entire right side was female, the left side being male. The colour pattern on the two sides was completely different, the male side corresponding to the concolorous phenotype, the female side to the contrasty one. The gonad was an undeveloped ovotestis, the testicular part being XO (2n = 23). There are two obvious explanations of this gynandromorph: (1) that a single XX zygote nucleus gave rise to XX and XO nuclei through loss of an X; in this case we would be dealing with a sex-linked pattern polymorphism, the gene for the contrasty morph being dominant to the concolorous allele; (2) that the gynandromorph arose from a binucleate egg, as a result of double fertilization. Data on the frequency of the morphs in the two sexes, in natural populations, do not support the first hypothesis, and it is concluded that the second one must be correct.

2018 ◽  
Author(s):  
Mathieu Gautier ◽  
Junichi Yamaguchi ◽  
Julien Foucaud ◽  
Anne Loiseau ◽  
Aurélien Ausset ◽  
...  

Many animal species are comprised of discrete phenotypic forms. Understanding the genetic mechanisms generating and maintaining such phenotypic variation within species is essential to comprehending morphological diversity. A common and conspicuous example of discrete phenotypic variation in natural populations of insects is the occurrence of different colour patterns, which has motivated a rich body of ecological and genetic research1–6. The occurrence of dark, i.e. melanic, forms, displaying discrete colour patterns, is found across multiple taxa, but the underlying genomic basis remains poorly characterized. In numerous ladybird species (Coccinellidae), the spatial arrangement of black and orange patches on adult elytra varies wildly within species, forming strikingly different complex colour patterns7,8. In the harlequin ladybird Harmonia axyridis, more than 200 distinct colour forms have been described, which classic genetic studies suggest result from allelic variation at a single, unknown, locus9,10. Here, we combined whole-genome sequencing, population genomics, gene expression and functional analyses, to establish that the gene pannier controls melanic pattern polymorphism in H. axyridis. We show that pannier, which encodes an evolutionary conserved transcription factor, is necessary for the formation of melanic elements on the elytra. Allelic variation in pannier leads to protein expression in distinct domains on the elytra, and thus determines the distinct colour patterns in H. axyridis. Recombination between pannier alleles may be reduced by a highly divergent sequence of ca. 170 kb in the cis-regulatory regions of pannier with a 50 kb inversion between colour forms. This likely helps maintaining the distinct alleles found in natural populations. Thus we propose that highly variable discrete colour forms can arise in natural populations through cis-regulatory allelic variation of a single gene.


1938 ◽  
Vol s2-81 (321) ◽  
pp. 107-126
Author(s):  
HELLEN PIXELL GOODRICH

1. The changes of shape in the protomerite sucker, together with the behaviour of the multiple caducous epimerites, have been observed in living specimens of Nina parasitizing Scolopendra subspinipes Leach in Bermuda and Malaya, and also Scolopendra cingulata Latreille from Banyuls (Mediterranean). 2. This gregarine, Nina, showed extraordinary variety of size and form in the same host specimen, but no constant differences could be discovered, in fact the gregarines appeared exactly alike morphologically from the three widely separated parts of the world. One is thus forced to the conclusion that they are all the same as Léger and Duboscq's species from Banyuls which they call Nina gracilis Grebnicki. [This will possibly prove finally to be Kdlliker's Nina scolopendrae.] 3. Scolopendra cingulata and Scolopendra subspinipes are said to be closely related species, and we appear to have in Nina a parasite which is phylogenetically older than at least one of these hosts. 4. The elaborate method for the dispersal of the spores in water or moist places is described with an approximate time table. One striking peculiarity is the retention of the epicyte of the gamonts inside the true cyst wall. After the microgametes have entered the female side of the cyst all communication between the two sides is closed. While the zygotes are develop ing into spores in the female side, the male side develops into a float, gradually swelling and causing the whole cyst to rise to the surface of the water. Finally, by rupture of all its envelopes the spore mass is ejected to a considerable distance.


1896 ◽  
Vol 42 (179) ◽  
pp. 787-790 ◽  
Author(s):  
A. R. Turnbull

My object in this paper is to give a brief note of a trial which has recently been made in the Fife Asylum, in the way of introducing female nursing in the male sick-room. Nursing is peculiarly woman's province; and it has, I believe, often been felt that it would be a great advantage if female care could be more freely utilised in the management of male insane patients, or at least of those of them who are suffering from special bodily disease in addition to the mental symptoms. The main objections to the step have hitherto been: (1) that some of the habits and peculiarities of the male insane may make it unfit or undesirable to have them under female care; and (2) that in many asylums the structural arrangement makes it difficult or impossible to bring the male sick-room under systematic supervision by the female staff. Lately it was necessary to build a large addition to the Fife Asylum; and advantage was taken of this opportunity to get rid of the second objection mentioned. The new building is a hospital block, and is intended to receive recent admissions, cases requiring special observation on account of their mental state, and cases of bodily illness. Each side (male and female) is divided into three sections: 1st, sickroom proper (for cases of bodily illness); 2nd, special observation ward (intended for new cases, and cases needing continuous supervision on account of suicidal or other dangerous tendency); and 3rd, general observation ward. There are the usual dining-hall, kitchen, and administrative rooms in the centre of the building. The male and female sick-rooms are placed next to the administrative portion, one on each side; and as the doors here are unlocked during the day, with free communication by the corridor, the male sick-room is easily reached from the female side, and is administered by the matron, the head nurse (who has charge of both sick-rooms), and two junior nurses. Each sick-room communicates with a special observation dormitory, beyond which again is the special observation day-room. This dormitory is empty during the day, but receives at night the cases which require continuous supervision on account of suicidal tendency, and which come to it direct from the special observation day-room. On the male side the door between the sick-room and the observation dormitory is kept locked during the day; and there is thus no direct communication between the sick-room and those parts of the male side which are under the charge of attendants, except by the general corridor. When the Medical Officer makes the evening visit, this door is unlocked, and the sick-room and observation dormitory are thrown into one and come under the charge of a male attendant, who is on duty during the whole night, while the nurses return to the female side of the building. This plan was followed because our numbers are too small to require separate attendance in the two rooms; and in this way the sick-room is under female care during the day, but is supervised at night by the male staff.∗


2019 ◽  
Vol 31 (2) ◽  
pp. 483-492
Author(s):  
Yu. B. Polidovych

The article is devoted to the analysis of images on the bone comb from the Haymanova Mohyla mound (IV century BC). The images on it quite fully represent the myth of a Hero fighting a dragon, which is not known from narrative sources. The first large plate (the «male» side of the comb) depicts a battle scene with a consistently developing plot: the defeat of one hero — the triumph of the dragon — revenge and the victory of the second hero. It can be assumed that the characters in this scene are Targitaos and Kolaxais, known from the story of Herodotus. These Scythian heroes relate to Iranian Yima (Jamshid) and Θraētaona (Fereydun). The goddess is reproduced on the second large plate (the «female» side of the comb). Her iconographic image was borrowed from the ancient Greek Art, but it was perceived by the Scythians, probably as the goddess Api (Άπί), equivalent to the Iranian goddess Aredvi Sura Anahita. The general context of the images suggests that the Scythians were familiar with the Iranian prayers to this goddess with a request to bestow good luck in the fight against hostile creatures. The comb was certainly an important ritual and status attribute.


2005 ◽  
Vol 53 (6) ◽  
pp. 353 ◽  
Author(s):  
DG Chapple

The life history and reproductive ecology of White’s skink, Egernia whitii, was examined in a population in the Australian Capital Territory using both field and genetic studies. Colour pattern polymorphism was evident within the population, with both patterned and plain-back morphs present. Lizards typically took 3 years to reach sexual maturity, with the size at maturity being ~75 mm snout–vent length (SVL) in both sexes. There was an even overall adult sex ratio, although a slight female-bias was evident in plain-back individuals. Sexual dimorphism was evident, with males having longer and wider heads, and females having larger body size. Females generally bred annually, with mating occurring in September–October and parturition in late January–February, although the litter was produced over several days (2–10 days, mean 4 days). Litter size ranged from one to four (mean of 2.5). There was a significant relationship between maternal SVL and both litter size and relative clutch mass, but these trends were not consistent between colour morphs. An inverse relationship between litter size and offspring size (SVL and mass) was found. Comparison of the results with previous investigations of E. whitii indicates substantial geographic variation in life-history traits that is presumably associated with latitudinal variation in climatic conditions.


2017 ◽  
Vol 16 (3) ◽  
pp. 229-244 ◽  
Author(s):  
Sara Ruane ◽  
Edward A. Myers ◽  
Kahmun Lo ◽  
Sara Yuen ◽  
Rachel S. Welt ◽  
...  

Biologia ◽  
2010 ◽  
Vol 65 (2) ◽  
Author(s):  
Selcuk Yurtsever ◽  
Nilgun Akdeniz ◽  
Burcu Karahalil

AbstractThe heritable elytral colour/pattern polymorphism of Philaenus spumarius in north-western Black Sea region of Turkey was investigated. A total of 2,530 adult spittlebugs, 1,020 females and 1,510 males were collected and analysed in terms of the 11 most common colour forms. Nine different phenotypes, expressed by six different alleles, were determined: populi (POP), typicus (TYP), trilineatus (TRI), marginellus (MAR), flavicollis (FLA), leucocephalus (LCE), gibbus (GIB), albomaculatus (ALB), and leucophtalmus (LOP). The common phenotypes lateralis (LAT) and quadrimaculatus (QUA) of previous studies were not encountered at all. The predominant phenotype was TYP (63%) in females and males followed by POP (31%). TRI (4%) and melanics (5%) were at close proportions. However, only one site had nine phenotypes altogether. The majority of the sites had only the POP and TYP morphs. The melanic forms were found only in females.


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