A GYNANDROMORPH OF RACHISPODA SUBPILIGERA (MALLOCH) (DIPTERA: SPHAEROCERIDAE), WITH NOTES ON ASYMMETRY, CIRCUMVERSION, AND THE STRUCTURE OF THE MALE POSTABDOMEN

1992 ◽  
Vol 124 (4) ◽  
pp. 729-735 ◽  
Author(s):  
Terry A. Wheeler
Keyword(s):  
Abdominal Segment ◽  
Developmental Process ◽  
Direct Consequence ◽  
Male And Female ◽  
Posterior Division ◽  
Anterior Posterior

AbstractA gynandromorph of Rachispoda subpiligera (Malloch) is described. The specimen exhibits both bilateral and anterior/posterior division of male and female genitalic components. Abdominal segment 5 is male, segments 6 and 7 are bilaterally divided into male (right) and female (left) halves, and segments 8–11 are female. Comparison of male and female components supports the view that the large, asymmetrical sclerite posterior to sternite 5 in male Sphaeroceridae is synsternite 6 + 7. Circumversion of the genitalia, normally seen in male segments 8–11, is absent, although male components of segments 6 and 7 exhibit asymmetry normally associated with circumversion. This suggests that asymmetry of sternites 6 and 7 is a developmental process independent of circumversion, not a direct consequence of circumversion.

scholarly journals Comparative genitalic morphology in ten genera of thread-legged bugs of the tribe Metapterini, and its phylogenetic importance (Hemiptera: Heteroptera: Reduviidae)

2018 ◽  
Vol 58 (1) ◽  
pp. 91-125 ◽  
Author(s):  
Valentina Castro-Huertas ◽  
Dimitri Forero ◽  
Jocelia Grazia
Keyword(s):  
Male Genitalia ◽  
Abdominal Segment ◽  
Data Matrix ◽  
Potential Usefulness ◽  
Bursa Copulatrix ◽  
Wing Polymorphism ◽  
Male And Female ◽  
Basal Process ◽  
Segment 8 ◽  
Assassin Bug

The assassin bug tribe Metapterini belongs to the subfamily Emesinae (Hemiptera: Heteroptera: Reduviidae). Morphologically, it is characterized by the conspicuous basal process of the posteroventral series in the foreleg and the presence of wing polymorphism, with a high proportion of the genera with micropterous or apterous species. Here, the male and female ectodermal genitalic structures are documented for ten genera and twenty-three species of Metapterini, including eight species of the speciose genus Ghilianella Spinola, 1850. Descriptions and digital macrophotographs are provided for abdominal segment 8, pygophore, parameres, and phallus of the male, and for tergite 8, tergite 9, gonocoxae, gonapophyses, gonoplac, and bursa copulatrix of the female. The asymmetric male genitalia within Emesinae are discussed. From this morphological documentation sixty six phylogenetic characters are coded, presented as a data matrix and analyzed cladistically, and their potential usefulness for resolving relationships among Metapterini is discussed.

A new species of Sparsorythus Sroka & Soldán, 2008 (Ephemeroptera: Tricorythidae) from Eastern Ghats of Southern India

Zootaxa ◽  
2021 ◽  
Vol 4915 (2) ◽  
pp. 237-245
Author(s):  
T SIVARUBAN ◽  
PANDIARAJAN SRINIVASAN ◽  
S BARATHY ◽  
M BERNATH ROSI ◽  
RAJASEKARAN ISACK
Keyword(s):  
New Species ◽  
Tamil Nadu ◽  
Abdominal Segment ◽  
Southern India ◽  
Eastern Ghats ◽  
Femur Length ◽  
Male And Female ◽  
Length Width ◽  
A New Species

A new mayfly species, Sparsorythus sivaramakrishnani sp. nov. from the stream of Pullian cholai, Thuraiyur, Namakkal district, Tamil Nadu, India is described based on male and female nymphs. Sparsorythus sivaramakrishnani sp. nov. differs from the closely related S. gracilis by the shape of the left prostheca, the number of bristle-like processes at base of left prostheca, the ratio and shape of right prostheca, the ratio of femur length: width, the size of the female nymph, the mesonotum overlapping in fifth abdominal segment of the female, and by the shape of hypopharyngeal lingua. 

Regeneration in the anterior—posterior axis of the insect thoracic segment

Development ◽  
1986 ◽  
Vol 98 (1) ◽  
pp. 137-165
Author(s):  
Vernon French ◽  
Tamara F. Rowlands
Keyword(s):  
Abdominal Segment ◽  
Adjacent Tissue ◽  
Local Pattern ◽  
Shortest Route ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Deletion Pattern ◽  
Boundary Model ◽  
Third Line ◽  
Anterior Posterior

After removal of a transverse strip of ventral thorax from the beetle, Tenebrio molitor, interaction occurred between epidermis posterior to the mesothoracic leg and that anterior to the metathoracic leg. Depending on the size and position of the excision, this interaction resulted in either the regeneration of the extirpated tissue or its replacement by an A/P reversed pattern of sclerites and supernumerary leg. By either route, local pattern continuity was restored between the normal meso- and metathoracic legs. Similarly, when a leg plus adjacent tissue was extirpated, continuity was restored by leg regeneration or by formation of an A/P reversed duplication of sclerites. The results of these strip excisions can be understood in terms of two current models of the ventral thorax (the Boundary Model and the Polar Coordinate Model), each of which postulates a distinct compartment or region intervening between the epidermis surrounding the bases of successive legs. However, the models do not explain the large differences in the frequency of formation of the duplication/deletion pattern after excisions of different widths. The results are also compatible with a different model, involving an A–P sequence of positional values similar to that proposed for the abdominal segment. Regeneration would restore continuity within the sequence by the shortest route, forming either the midsegment (including the leg) or the intersegmental region. The meso- and metathorax differ in the structure of the ventral sclerites and in the segmentation of the tarsus of the leg. The structures regenerated after the various excisions show that the segment border is not crossed during regeneration and indicate that an A/P compartment border running through the leg is usually also respected. There is no sign, however, of a third line of lineage restriction that would indicate a subdivision of the segment into three compartments (as proposed in the Boundary Model).

scholarly journals Description of the puparium and adult genitalia of Dactylodeictes brevifacies James, 1974 (Diptera: Stratiomyidae)

2020 ◽  
Vol 60 ◽  
pp. e20206028
Author(s):  
Lara Duarte Piau Braga ◽  
Welinton Ribamar Lopes ◽  
José Roberto Pujol-Luz
Keyword(s):  
Adult Male ◽  
Related Species ◽  
New Record ◽  
Abdominal Segment ◽  
Ventral View ◽  
Gallery Forest ◽  
Closely Related Species ◽  
Male And Female ◽  
Cerrado Vegetation

The puparium of Dactylodeictes brevifacies was described based on fifty-eight specimens reared in laboratory until the emergence of adults. Larvae were collected under the bark of fallen trees in a Cerrado vegetation, Gallery forest; Palm swamp (Vereda) and open grassland (Campo Limpo) in States of Goiás and Tocantins, Brazil (New Record). The puparium was compared with that of Brachyodina lopesi, the most closely related species with a described puparium. Despite this species clearly shared the larval pachygastrinae features it has a remarkable character not know before for this subfamily: the presence of four pairs of ventral setae (V) in the eighth abdominal segment in ventral view, while in other larvae and puparia of this subfamily, there are five pairs of ventral setae. The adult male and female were described and figured.

scholarly journals Gap genes are involved in inviability in hybrids between Drosophila melanogaster and D. santomea

2021 ◽  
Author(s):  
Wenhan Chang ◽  
Martin Kreitman ◽  
Daniel R. Matute
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Network ◽  
Developmental Process ◽  
Coding Region ◽  
Pure Species ◽  
Closely Related Species ◽  
Hybrid Inviability ◽  
Gap Gene ◽  
Gap Genes ◽  
Anterior Posterior

ABSTRACTEvolved changes within species lead to the inevitable loss of viability in hybrids. Inviability is also a convenient phenotype to genetically map and validate functionally divergent genes and pathways differentiating closely related species. Here we identify the Drosophila melanogaster form of the highly conserved essential gap gene giant (gt) as a key genetic determinant of hybrid inviability in crosses with D. santomea. We show that the coding region of this allele in D. melanogaster/D. santomea hybrids is sufficient to cause embryonic inviability not seen in either pure species. Further genetic analysis indicates that tailless (tll), another gap gene, is also involved in the hybrid defects. giant and tll are both members of the gap gene network of transcription factors that participate in establishing anterior-posterior specification of the dipteran embryo, a highly conserved developmental process. Genes whose outputs in this process are functionally conserved nevertheless evolve over short timescales to cause inviability in hybrids.

Memoirs: Notes on the Structure and Development of the Reproductive Organs in Philaenus spumarius L

1932 ◽  
Vol s2-75 (299) ◽  
pp. 467-481
Author(s):  
MARGOT E. METCALFE
Keyword(s):  
Abdominal Segment ◽  
Ejaculatory Duct ◽  
Reproductive Organs ◽  
Accessory Gland ◽  
Male And Female ◽  
Philaenus Spumarius ◽  
Efferent System

1. The genitalia are paired in origin and appear to represent, in the male the coxites and telopodites of the ninth abdominal segment; in the female the telopodites of the eighth, and the coxites and telopodites of the ninth segments. 2. The testes and vasa deferentia, ovaries and oviducts, are paired and mesodermal in origin. 3. The efferent system, other than the testes and vasa deferentia, ovaries and oviducts, is unpaired and ectodermal in origin. 4. The gonopore is serially homologous in the male and female; but is posterior to the ninth segment in the former, and posterior to the eighth segment in the latter. 5. The ejaculatory duct and the median uterus are not strictly homologous, the ejaculatory duct being more comparable with the median accessory gland in the female. 6. There seems to be, in the females of the Insecta, a tendency for the gonopore to be shifted posteriorly.

VISUAL DETERMINATION OF SEX OF DIAMONDBACK MOTH LARVAE

1997 ◽  
Vol 129 (3) ◽  
pp. 585-586 ◽  
Author(s):  
Yong-Biao Liu ◽  
Bruce E. Tabashnik
Keyword(s):  
Abdominal Segment ◽  
Diamondback Moth ◽  
External Genitalia ◽  
Development Rate ◽  
Fourth Instar ◽  
Male And Female ◽  
Lepidopteran Larvae ◽  
Genital Discs ◽  
Different Strains

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major worldwide pest of cruciferous vegetables (Talekar and Shelton 1993). Male and female adults of this species can be accurately identified by visible differences in their external genitalia. According to Robertson (1939), the sex of pupae can also be identified, but, in our experience, this approach is more difficult. For some types of research, determination of larval sex would be useful. For example, one could determine sex-specific responses of larvae to a treatment by observing mortality, development rate, or behavior of male and female larvae separately. In studies requiring hybrid mating between different strains of diamondback moth (Tabashnik et al. 1992), one could isolate groups of male larvae separately from female larvae to avoid mating within a strain. Some lepidopteran larvae can be sexed by the gonads being visible through the cuticle of the fifth abdominal segment or by the position of external pits marking the location of the genital discs in the eighth and ninth abdominal segments (Stehr 1987). But, because of their small size, it is not practical to sex diamondback moth larvae by external pits and we have found no studies in which male and female larvae were identified by gonadal form. Herein we report that third- and fourth-instar larvae of diamondback moth can be sexed efficiently and reliably.

Extent and properties of the regeneration field in the larval legs of cockroaches (Leucophaea maderae)

Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 69-79
Author(s):  
Horst Bohn
Keyword(s):  
Abdominal Segment ◽  
Anterior Margin ◽  
Posterior Border ◽  
Anterior Border ◽  
Leucophaea Maderae ◽  
Anterior Half ◽  
Regenerative Ability ◽  
Transplantation Experiments ◽  
Anterior Posterior

The investigation of the regeneration field of the larval legs of cockroaches (Leucophaea maderae), which commenced in a previous paper with extirpation experiments, has been continued by transplantation experiments. The extirpation experiments showed that there are two regions near the leg which are indispensable for leg regeneration: the basal sclerites, and the membranous region extending behind the leg up to the spiracle of the next segment, called ‘leg-inducing membrane’ (LIM). The LIM is followed by ‘sclerite-inducing membrane’ (SIM) which, upon contact with sclerites, only allows formation of sclerite structures. The results of the extirpation experiments have been confirmed by transplantation experiments. When the whole leg including the basal sclerites is removed, no leg regeneration occurs. The regenerative ability can be restored by implantation of part of the basal sclerites (for instance, the trochantin), but leg regeneration takes place only when the implantation area is covered by LIM. When the sclerites are transplanted to a region which is covered by SIM only additional basal sclerites are formed. Whole sets of basal sclerites have been implanted at different distances behind the uninjured hindleg. Additional legs are regenerated only in the anterior half of the membranous field extending between the hindleg and the first abdominal segment. Thus, there is adistribution of LIM and SIM in the region of the hindleg, similar to that near the midleg. Whole sets of basal sclerites have been implanted at various sites on the dorsal or ventral surfaces of the abdomen. Legs are formed on both surfaces, but only when the transplanted sclerites contact the intersegmental membranes. This means that the intersegmental membranes of the abdomen also have leg-inducing capacities. The implantation of a trochantin into a field of LIM is followed by the development of two regenerates - a normal one at the posterior border of the field, and one with reverse anterior-posterior polarity at the anterior border. When the trochantin is transplantedtogether with the praecoxa in a similar way, only one normal regenerate is formed at theposterior margin of the trochantin. The praecoxa prevents contact of the anterior margin of the trochantin with LIM, and contact of the anterior margin of the praecoxa with LIM does not promote leg regeneration.

Gender Influences Gait Asymmetry following Bicruciate-Retaining Total Knee Arthroplasty

2019 ◽  
Vol 33 (06) ◽  
pp. 582-588 ◽  
Author(s):  
David Hennessy ◽  
Paul Arauz ◽  
Christian Klemt ◽  
Shuai An ◽  
Young-Min Kwon
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Imaging System ◽  
Knee Kinematics ◽  
Male And Female ◽  
Female Patients ◽  
Total Knee ◽  
Bcr Tka ◽  
Anterior Posterior

AbstractThis is an experimental study. Gender has been reported to influence outcomes in patients with total knee arthroplasty (TKA) for knee osteoarthritis (OA). However, the influence of gender on three-dimensional (3D) in vivo kinematics during gait remains unclear. This study aimed to determine if 3D gait kinematics, including 3D knee translations and rotations, differed in men and women following bicruciate-retaining (BCR) TKA. Twenty-nine well-functioning unilateral BCR TKA patients (14 males and 15 females) underwent evaluation of both knees during level walking on a treadmill at a self-selected speed using a dual fluoroscopic imaging system. Interlimb comparisons of in vivo 6 degree-of-freedom kinematics were compared between male and female patients. Differences of pre- and postoperative Knee Society scores (KSSs) were compared between the groups. Both groups were matched regarding age and body mass index. Both male and female patients demonstrated improvement in their postoperative KSSs. Statistically significant differences were observed with respect to spatiotemporal anterior–posterior interlimb translations (p < 0.05). Although females presented more femoral posterior translation in the operative knee than the nonoperative knee during most of the stance phases (2.8 vs. −1.6 mm), males exhibited less femoral translation in the operative knee than the nonoperative knee (2.3 vs. −1.8 mm), when interlimb differences were detected during stance phase. Results demonstrated that there are 3D motion asymmetries of the knee in both male and female unilateral BCR TKA patients during gait with anterior–posterior interlimb asymmetries significantly greater in female than male participants. This suggests that gender may influence the in vivo knee kinematics in BCR TKA patients during gait.

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