Improvement on molecular sex identification primers for Passeriform bird species

The primer pair sex1/sex2,which can be widely applied for sex identification in Galliform species,was used to determine the sex of 17 Passeriform species.As CHD-W fragments tended to be preferentially amplified,which may cause unnecessary misidentification in bird species with little difference between CHD-Z and CHD-W,we modified sex1 and sex2,obtaining sex1' and sex-mix respectively.Primer sets were then recombined to conduct sex identification.After testing several Passeriforme birds of known sex,we found that the primer pair sex1'/sex2 was better at limiting the preferential amplification of CHD-W fragments.As they are being frequently used in sex allocation study of Aegithalos concinnus and song learning research of Lonchura striata,we can expect more applications of this primer pair to further studies in Passeriformes.

Progress in Sex Identification of Early Embryo of Livestock

Principle, research, and problems of techniques for sex identification of early embryo of livestock were discussed in detail from aspects of main ways for sex control, main methods for sex identification of early embryo, and application of sex identification in livestock production. And development prospects were expected.

Sex Identification of Red-crowned Crane by the Polymerase Chain Reaction

Sex determining gene primers of Oriental White Stork were used to amplify sex-linked gene of the Red-crowned Crane′s W chromosome-specific by PCR for sex identification. The sexes of 7 couples of grown Red-crowned Cranes and 15 youngs were identified. Through DNA sequence analysis, the identity is 94.77% between Red-crowned Crane and Oriental White Stork. The results of this study suggest that the application of the polymerase chain reaction technique is practicable for determining sex in the Red-crowned Crane.

Identification of the Sex of Earlier Embryos from Generic Hybrids of Chicken-Quail by Wpkci

In this study, a protocol was developed to identify the sex of earlier embryos of chicken （♂）-quail （♀） hybrids and successfully tested the sex proportion of each period （66-120 h）. We acquired cross bred eggs by artificial insemination, hatched them in the same batch according to the standard hatching condition of chicken, and collected earlier living embryos at 66, 72, 78, 84, 90, 96, 102, 108, 114, and 120 h randomly. We adopted RT-PCR protocol and multiple PCR, made the known sex quail as the external control, employed fl-actin as the internal control, and used primers that were designed according to conservative area of gene Wpkci of quail to identify the sex of earlier hybrid embryos. The results indicated that the primer of Wpkci can be used to identify the sex of hybrid embryos accurately; there were more male than female in earlier embryos, the sex proportion of earlier embryos compared with academic numerical value was significantly different （P〈0.01）, and there was no difference between different periods （P〉0.05）. In the present study, we concluded that a simple, fast, credible and stable protocol to identify the sex of earlier hybrids embryos had been established by using primer of Wpkci; in earlier embryos, the death rate of female was higher than that of male and there was no fluctuant peak.

Morphometric and Volumetric Evaluation of Maxillary Sinus as an Aid in Sex Identification in Forensic Odontology-A Cone-Beam Computed Tomography Study

Background:Various methods are used in forensic odontology for the purpose of sex and personal identification.Some of them include cheiloscopy,rugoscopy,mandibular measurements,and study of paranasal sinuses.In our study,we have used maxillary sinus as an aid in sex identification.For this purpose,we have evaluated the morphometric and volumetric measurements of the maxillary sinus using a 3-Dimensional imaging modality,Cone Beam Computed Tomography.Aims and Objectives:Sex and age identification are important in the process of identification of both the living and the dead.Hence,this transverse retrospective study was done to appraise the precision of the dimensions and volume of the maxillary sinus to aid in sex and age identification.Material and Methods:Eighty full Field of View(FOV)Cone-Beam Computed Tomography(CBCT)images were retrieved from the archives which were matched with age and sex.The maxillary sinuses on either side were measured mediolaterally in the axial section and supero-inferiorly in the coronal section.The volumetric analysis of the sinus was done in the sagittal section.The sex was classified using discriminant function analysis and the differences were compared using independent t-test.The differences with age were analyzed using one-way ANOVA.Results:Independent t-test was done for comparison of the sinuses between both sexes.Maxillary sinuses measurements were larger among the males both superior-inferiorly on either side(P<0.001)and mediolaterally on the right(P<0.049)showed statistically significant values.A significant correlation existed while comparing the maxillary sinus volume among both the sexes on either side(P<0.001 and<0.002 in the case of right and left respectively).On comparing the supero-inferior and mediolateral measurements and the maxillary sinus volume on either side among the various age groups,the values were statistically insignificant.Present study shows that the maxillary sinus measurements using Cone-beam computed tomography were diagnostic in the identification of sex but not in age estimation and can be used in forensic dentistry.

Study on the sex-related AFLP marker of the Yangtze finless porpoise

The sex-related molecular marker of the Yangtze finless porpoise was screened using Amplified Fragment Length Polymorphism (AFLP) technique combined with the bulked segregant analysis. Totally 36 AFLP primer combinations were used to detect the genome DNA bulks of the female and male porpoises, and one sex-related AFLP marker was finally obtained. The marker can be applied to sex identification, and provides a base for further cloning of sex-related genes and analyzing of Y chromosome haplotypes of the Yangtze finless porpoise.

Analysis of the Offspring Sex Ratio of Chicken by Using Molecular Sexing

The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.

A New Detecting Method for the Sequence Difference of CHD1 Gene on Sex Chromosomes Z and W in Domesticated Ducks of China

A new method for detecting the sequence differences of duck Chromo-helicase-DNA-Binding 1 （ CHD1 ） genes on sex chromosomes Z and W was established by amplifying DNA fragment length poly morphism, which aimed to solve some technical problems, such as the sex identification with nondamage, the misclassifc rate of artificial sex identification during embryonic period, and the injury caused by anal reversal identification method during neonatal period. The im- proved sex identification method was developed by DNA amplified fragment length polymorphism by using CHD1 gene sequence in bird. The sex identification PCR primers YPF/YPR were used, and the PCR product was cloned, sequenced and blasted; and the effectiveness and accuracy of this method were verified through liv- ing examples. 2% agarose gel electrophoresis was used to distinguish 495 bp CHD1-Z and 351 bp CHD1-W obtained by primer YPF/YPR. The female （ZW） dis- played two visible bands; while male （ZZ） had only one single band. It was proved that this method for detecting the sequence differences of duck CHD1 gene was visual and reliable, and the molecular marker provided was effective and precise in the sex molecular biological identification of domesticated duck in China.

Isolation of Fetal Nucleated Red Blood Cells from Maternal Blood

To find a simple, effective method of isolating fetal cells from maternal peripheral blood for prenatal diagnosis, 45 women were studied with their gestation being 6-14 weeks and age 21- 30 years. The fetal cells were isolated from maternal blood by using discontinuous density gradient centrifugation. Some of the isolated cells were made smear and counted under the microscope; others were used for predicting fetal sex by PCR amplification of Y chromosome specific DYZ1 gene. The major cells in the upper separation interface were lymphocytes and monocytes, with occasionally seen nucleated red blood cells (NRBC); while those in the middle separation interface were neutrocytes, with NRBC scattering. The ratio of NRBC/nucleated cells was 1. 98±0. 28× 10-5. There was no significant difference between the first and second trimester (P>0. 05). The amount of isolated fetal cells was sufficient for prenatal genetic diagnosis. Male pregnancy was correctly predicted in 10 out of 13 cases. It is concluded that the method of discontinuous density gradient centrifugation was of considerable importance in the development of non-invasive prenatal genetic diagnosis.