Sexing

Sex determination mechanisms, differing in their modality, are widely represented in all
the various animal taxa, even at the intraspecific level. Within the highly diversified class Insecta,
Drosophila has been used to unravel the molecular and genetic mechanistic interactions that are involved
in sex determination. Indeed, the molecularly characterized genes of the Drosophila sex determination
hierarchy X:A > Sxl > tra > dsx have been fruitful starting points in the cloning of homologous genes from
other insect species. This genetic cascade seems to control sex determination in all Drosophila species. Sex
determination in the tephritid Mediterranean fruit fly Ceratitis capitata (Wiedemann), which diverged from
Drosophila 90-100 million years ago, contrasts to that found in Drosophila. A different primary signal, a
Y-linked male-determining factor (M), still to be molecularly identified, dictates maleness whereas in
Drosophila, the primary signal is the X:A (X chromosome:autosome) balance. However, the Drosophila
sex-determining pathway, apart from the X:A > Sxl initial regulatory segment, is functionally conserved in
C. capitata. The tra gene (Cctra) of C. capitata, as in Drosophila, is the master gene for femaleness
through its regulation of the dsx gene and it is dispensable for maleness. In contrast to Drosophila however,
where tra is a subordinate target of Sxl, Cctra seems to initiate an autoregulatory mechanism in XX
embryos that provides continuous tra female-specific function and acts as a cellular memory maintaining
the female pathway. Indeed, a transient interference with Cctra expression in XX embryos by RNA interference
(RNAi) treatment can cause complete sexual transformation of both germ-line and soma in adult
flies, resulting in fertile XX pseudomales. The development of new transgenic sexing strains of C. capitata
able to produce male-only progeny following heat-shock treatments is now feasible and a concrete possibility.
Evolutionary considerations strongly suggest that this biotechnological strategy to produce maleonly
progeny could be developed for many other Tephritidae and other dipteran species where the sterile
insect technique (SIT) is employed within the framework of area-wide integrated pest management programmes.

This study was conducted using B-mode transrectal (TR) and transabdominal (TA) ultrasonography to determine early pregnancy and fetometry. A total of 110 does aged between 8 and 36 months were used. The detection of early pregnancy and foetal number was measured. The relationship between gestation age and crown-rump length (CRL) and bi-parietal diameter (BPD) was determined from days 40 to 109 of gestation. The accuracy of foetal sexing was determined by differentiation of genital tubercle (GT) from days 40 to 109 of gestation and then followed up after birth. The examination revealed 95.5% of does were pregnant, with 100% accuracy in detecting pregnancy for positive cases. The foetal number was 45.7% and 54.3% for single and twins/triplets. The TR probe enabled more reliable and early recognition of foetal fluid (5 days) and heart beats (4 days) than the TA probe. The TR observation of heart beats is recommended as conclusive evidence of the presence of a live foetus. The TA convex probe was used from days 40-89 to measure CRL and from days 40-109 to measure BPD. The relation between gestational age and CRL or BPD were highly significant (p<0.0001). The accuracy of sex identification among the three groups was not significantly (p>0.05) higher in single, compared to multiple pregnancies. In total, 83.3% and 70.2% of single and twins and triplets were sexed. After birth, one case was misdiagnosed by ultrasound, i.e. 83.3% (single) and 68.4% (twins and triplets) were sexed. However, identification of GT in male foetuses was possible from day 40 onwards. From a total 105 scanned does, 80 (76.2%) were sexed and 75.2% of cases were sexed after birth. B-mode real-time ultrasonography is recommended as a reliable means that can be used in field conditions to provide early detection of gestation as early as 19-27 days after mating, for CRL or BPD measuring and foetal sexing from day 40 of gestation onwards.

En muchas especies es imposible distinguir visualmente los sexos, si bien en algunas de
ellas, machos y hembras muestran pequeñas, pero cuantificables, diferencias  biométricas que pueden usarse para discriminarlos. Este es el caso del grupo de los mosquiteros Phylloscopus, en los que se usa la longitud alar para distinguir los sexos. Hemos desarrollado un método en el que además del ala se tiene en cuenta el tarso y en el que mediante probabilidades multivariantes hemos aumentado la proporción de individuos que se pueden discriminar en tres especies: mosquitero común P. collybita, mosquitero musical P. trochilus y mosquitero ibérico P. ibericus. Además, nuestro método de sexado no tiene sesgos hacia uno de los dos sexos. El objetivo de este artículo es ofrecer una guía práctica para la implementación de nuestro método usando el software libre R.

The partial skeletons of 79 medieval cats were recovered from a well in Cambridge, England. The animals had been killed by having their throats cut and were subsequently skinned and dismembered for consumption by the inhabitants of the town. A metrical study revealed the small stature of the cats in comparison with those from medieval Colchester and late medieval and early post-medieval Norwich, while an allometric analysis showed that the build of the animals was different from those excavated at the early medieval town of Haithabu, Germany, where even the female cats were much larger than the Cambridge males. Both the Haithabu and Cambridge cat assemblages are composed of almost equal proportions of males and females and this, certainly in the case of the Cambridge sample argues against the slaughtered animals having been held in captivity.

This thesis investigates and compares three cases of female graves, each of which had a sword as a burial gift.
On the basis of this research, it will be examined whether archaeologists have often mis-sexed remains throughout Scandinavian history.
A term is also given to this concept and further demonstrated trough examples and possible reasons.

Objectives: We aim to provide an understanding of the psychological sequela of androgen insensitivity syndrome (AIS) in phenotypic females in order to begin to inform psychosocial health care services.

Design: Eight adult women with AIS were recruited through the Androgen Insensitivity Syndrome Support Group-United Kingdom (AISSG-UK). Data was collected via two semi-structured interviews with each woman.

Methods: Transcripts were analysed using grounded theory and a conceptual model was developed which suggests a way of understanding the AIS distress experienced by the participants.

Results: The pivotal concept is a woman's fear of devaluation. This is connected to her level of adaptation and perception of having a compromised womanhood. These, in turn, are related to her medical management and involvement with others via a support group and in talking about AIS.

Conclusions: Participants showed a clear preference for open communication about their condition throughout the process of medical management. We recommend sensitive, pacing of information to allow young women and their families to make informed decisions about treatment and a realistic adaptation to life with AIS.

Measurements taken on 47 complete and 44 distal fragments of cattle metacarpals from 17th century AD Carnide, Lisbon, separate into two groups. Comparison with 21 ancient DNA sexed specimens and modern specimens of known sex (seven Barrosã cows and a Barrosã bull), indicates that the Carnide metacarpals probably belonged to both cows and bulls/oxen. We use the 47 complete metacarpals as a “sexed reference sample” in order to find which measurements generally taken by zooarchaeologists on the distal metacarpal help separate males from females. Widths appear to be most useful. The modern Barrosã cattle in our collection, selected for their meat, have wider metacarpals than the ones from Carnide; the latter were perhaps more generalist animals.

Patent application: PCT/IB02/00693
This invention refers to the identi?cation of the Cctra gene
(SEQ.ID.NO. 1) and to corresponding dsRNA molecules
comprising Cctra gene.sequences as a tool to produce only
rnale progeny in the Mediterranean fruitfly Ceratitis capitata.

Sex determination mechanisms, differing in their modality, are widely represented in all the various animal taxa, even at the intraspecific level. Within the highly diversified class Insecta, Drosophila has been used to unravel the molecular and genetic mechanistic interactions that are involved in sex determination. Indeed, the molecularly characterized genes of the Drosophila sex determination hierarchy X:A &gt; Sxl &gt; tra &gt; dsx have been fruitful starting points in the cloning of homologous genes from other insect species. This genetic cascade seems to control sex determination in all Drosophila species. Sex determination in the tephritid Mediterranean fruit fly Ceratitis capitata (Wiedemann), which diverged from Drosophila 90-100 million years ago, contrasts to that found in Drosophila. A different primary signal, a Y-linked male-determining factor (M), still to be molecularly identified, dictates maleness whereas in Drosophila, the primary signal is the X:A (X chromosome:a...

The transformer gene in Ceratitis capitata (Cctra ep ) is the founding member of a family of related SR genes that appear to act as the master epigenetic switch in sex determination in insects. A functional protein seems to be produced only in individuals with a female XX karyotype where it is required to maintain the productive mode of expression through a positive feedback loop and to direct female development by instructing the downstream target genes accordingly. When zygotic activation of this loop is prevented, male development follows. Recently, tra ep orthologues were isolated in more distantly related dipteran species including Musca domestica, Glossina morsitans and Lucilia cuprina and in the Hymenopterans Apis mellifera and Nasonia vitripennis. All of these tra ep orthologues seem to act as binary switches that govern all aspects of sexual development. Transient silencing leads to complete masculinization of individuals with a female karyotype. Reciprocally, in some systems it has been shown that transient expression of the functional TRA product is sufficient to transactivate the endogenous gene and implement female development in individuals with a male karyotype. Hence, a mechanism based on tra ep epigenetic autoregulation seems to represent a common and presumably ancestral single principle of sex determination in Insecta. The results of these studies will not only be important for understanding divergent evolution of basic developmental processes but also for designing new strategies to improve genetic sexing in different insect species of economical or medical importance.

The transformer gene in Ceratitis capitata
(Cctraep) is the founding member of a family of related SR
genes that appear to act as the master epigenetic switch in
sex determination in insects. A functional protein seems to
be produced only in individuals with a female XX karyotype
where it is required to maintain the productive mode
of expression through a positive feedback loop and to
direct female development by instructing the downstream
target genes accordingly. When zygotic activation of this
loop is prevented, male development follows. Recently,
traep orthologues were isolated in more distantly related
dipteran species including Musca domestica, Glossina
morsitans and Lucilia cuprina and in the Hymenopterans
Apis mellifera and Nasonia vitripennis. All of these traep
orthologues seem to act as binary switches that govern all
aspects of sexual development. Transient silencing leads to
complete masculinization of individuals with a female
karyotype. Reciprocally, in some systems it has been
shown that transient expression of the functional TRA
product is sufficient to transactivate the endogenous gene
and implement female development in individuals with a
male karyotype. Hence, a mechanism based on traep epigenetic
autoregulation seems to represent a common and
presumably ancestral single principle of sex determination
in Insecta. The results of these studies will not only be
important for understanding divergent evolution of basic developmental processes but also for designing new strategies
to improve genetic sexing in different insect species
of economical or medical importance.

Microscopic analysis of bones, teeth, and other animal hard tissue can yield considerable information. The most intensively studied of such structures are growth rings and osteons. "Growth rings" accrue to the periosteal surface of many bones as well as in teeth, reflecting annual and shorter periods. Where bone rebuilding has not destroyed them, they can often provide an accurate ageing device despite some problems with readability. The mandible is generally the best bone for this kind of ageing. Various vertebrates have been studied, with differing degrees of accuracy. “Osteons” refers to systems of conduits (and associated structures) for small blood vessels and nerves that grow and run lengthwise in much compact bone of many vertebrates. Osteons respond to the stress and strain of life, and this allows for their use in ageing bones. Various bones, e.g. femur, humerus, and rib, have been used with differing degrees of success and accuracy. Two general approaches are used: quantitative and qualitative. The latter, used in continental Europe, appears to be easier, more objective, and probably more accurate, but both consist of determining the relative frequency or area of various kinds of osteons, their parts and/or their fragments. Much less effective and concerted have been attempts to use osteons for sexing, though under certain conditions this can be done. The methods and techniques commonly used for studying osteons, including the preparation of thin-sections with a microtome or taking of microradiographs, are not very difficult, but they do take some time to learn and to carry out. Advantages of using osteons include their being relatively resistant to fire and other abuses common to archaeological settings, their being able to be studied in small fragments of bones, and their presence in robust bones. Most but not all osteon work dealing with ageing and sexing has been done on human materials. A definite need exists for extending these efforts to more taxa, especially other long-lived ones and ones with marked sexual dimorphism.



[I'm not sure what her point is here. - KD]

Here we present the results of applying the method of non-contact sexing of birds by the profile beak outlines to a rare flightless rallid from New Zealand – takahē. The graphic stage of the method made it possible to identify visual differences in the profile outlines of the beak of males and females. The reliability of the differences found was confirmed by a set of statistical analysis techniques that showed almost 100 percent effectiveness of the proposed method.

The transformer gene in Ceratitis capitata (Cctra ep ) is the founding member of a family of related SR genes that appear to act as the master epigenetic switch in sex determination in insects. A functional protein seems to be produced only in individuals with a female XX karyotype where it is required to maintain the productive mode of expression through a positive feedback loop and to direct female development by instructing the downstream target genes accordingly. When zygotic activation of this loop is prevented, male development follows. Recently, tra ep orthologues were isolated in more distantly related dipteran species including Musca domestica, Glossina morsitans and Lucilia cuprina and in the Hymenopterans Apis mellifera and Nasonia vitripennis. All of these tra ep orthologues seem to act as binary switches that govern all aspects of sexual development. Transient silencing leads to complete masculinization of individuals with a female karyotype. Reciprocally, in some systems it has been shown that transient expression of the functional TRA product is sufficient to transactivate the endogenous gene and implement female development in individuals with a male karyotype. Hence, a mechanism based on tra ep epigenetic autoregulation seems to represent a common and presumably ancestral single principle of sex determination in Insecta. The results of these studies will not only be important for understanding divergent evolution of basic developmental processes but also for designing new strategies to improve genetic sexing in different insect species of economical or medical importance.

The agricultural pest Ceratitis capitata, also known as the Mediterranean fruit fly or Medfly, is a fruit crop pest of
very high economic relevance in different continents. The strategy to separate Ceratitis males from females (sexing)
in mass rearing facilities is a useful step before the sterilization and release of male-only flies in Sterile Insect
Technique control programs (SIT). The identification of genes having early embryonic male-specific expression,
including Y-linked genes, such as the Maleness factor, could help to design novel and improved methods of
sexing in combination with transgenesis, aiming to confer conditional female-specific lethality or female-to-male
sexual reversal.
We used a combination of Suppression Subtractive Hybrydization (SSH), Mirror Orientation Selection (MOS) and
differential screening hybridization (DSH) techniques to approach the problem of isolating corresponding mRNAs
expressed in XX/XY embryos versus XX-only embryos during a narrow developmental window (8-10 hours after
egg laying, AEL ). Here we describe a novel strategy we have conceived to obtain relatively large amounts of
XX-only embryos staged at 8-10 h AEL and so to extract few micrograms of polyA+ required to apply the complex
technical procedure. The combination of these 3 techniques led to the identification of a Y-linked putative gene,
CcGm2, sharing high sequence identity to a paralogous gene, CcGm1, localized either on an autosome or on the
X chromosome.
We propose that CcGm2 is a first interesting putative Y-linked gene which could play a role in sex determination.
The function exterted by this gene should be investigated by novel genetic tools, such as CRISPR-CAS9, which will
permit to