It has been claimed that artificial insemination (AI) of cows with frozen-thawed semen treated with commercially produced kits, Wholemom (in favour of female gender) increases the birth chance of calves with desired sex ratio by approximately 85% without decrease of pregnancy rates. Hence, this study was conducted to investigate the efficacy of wholemom kits as combined with frozen-thawed bovine semen during in vitro fertilization on the in vitro fertilization and developmental efficiency and sex ratios such as some reproductive parameters in bovine. For this, 1,737 oocytes were in vitro fertilized and developed. Agglutination effects on bovine after treatment of Wholemom kit were observed by time passage and dose respectively. To determine sex of embryos, Bovine embryo Y-specific gene primers(ConEY) and Bovine specific universal primer(ConBV) were used as multiple PCR method. Fertilization rate of wholemom-treated group was significantly lower than its of control group[66.9% (1,156/1,737) in Wholemom-treated group; 75.0% (610/813) in control group]. However, developmental rate after fertilization of both wholemom-treated and control groups were not significantly different [26.1% (404/1,156) in Wholemom-treated group; 27.4% (224/610) in control group]. Sex ratio of in vitro fertilized embryo with frozen-thawed semen treated with wholemom kit was determined by multi PCR. Female ratio in wholemom-treated group [85.4% (173/201)] was significantly higher than its of control group [47.2% (66/141)]. In conclusion, wholemom treatments of semen used in the in vitro fertilization and development of bovine oocytes provided increase in female ratio with decrease of fertilization rate.

The nesting behavior, reproduction, fruit set and shape of O. cornifrons varied significantly with the released sex ratio of O. cornifrons. A female : male sex ratio of 1 : 2 was resulted in a 3.4 to 6.7 fold higher than other sex ratio in a nesting behavior. A ratio of 1 : 2 resulted in a 1.2-fold nesting rate, which was slightly higher than other nesting rates. Releasing only males resulted in a 2.4-fold greater amount of fruit set in non-pollinated sites. A sex ratio of 1 : 2 gave a slightly higher shape index and a 1.2 to 1.6-fold lower asymmetric index than other sex ratios. There was no significant difference between female release numbers in fruit set, and 100 to 200 females gave a slightly higher shape index than 400 females. Thus, we determined that 200 females should be released per 2,000㎡ and that the sex ratio of females to males should be 1 : 2.

Increase of bovine embryos produced by in vitro fertilization (IVF) has been seen. The main reason for producing in vitro fertilized embryos in Korea has been to utilize the genetics of cows with higher carcass grade. Ovaries are collected from the cows in the slaughter house and the information on the carcass grade of the cow can be traced. Embryos produced from cows with higher carcass grade have been favored by the farmers. PCR has been one of the main techniques for sex determination of embryos targeting various genes. Bovine sex determining region Y (SRY) is specific to Y chromosome. However, it requires a control gene for PCR, if the embryo is female. In comparison to SRY, amelogenin can be amplified from male or female embryos with different fragment sizes due to differential splicing in all bovidae. The goal of this study was to determine whether there are any differences in the sex ratio of embryos produced in vitro and to compare the efficiency of sex determination using PCR. Ovaries of Hanwoo were collected and transported to the laboratory in thermal bottles. For in vitro maturation, oocytes were collected from the follicles with less than 8 mm of diameter and placed in either the Brackett & Oliphant media (BO), Tissue culture medium-199 (TCM-199), or IVMD101 media, containing 3% fetal bovine serum (FBS), 0.5 mg/ml FSH, 0.5 mg/ml LH, and 1 mg/ml estradiol-17β. For IVF, frozen sperm from Hanwoo bulls were used. After 22-24h IVF, embryos were transferred and cultured either in BO or TCM-199 with 10% FBS until the embryos were hatched. Hatched blastocysts were stored in PBS frozen, and later thawed and treated with embryo lysis buffer. After isolating genomic DNA, it was used for PCR using primers for casein beta (CSN2), as PCR control, or for male specific SRY primers. Alternatively, primers for amelogenin were used. Sex of embryos was determined and the sex ratio was analyzed. Out of 94 embryos, sex of 83 embryos (88.3%) was determined and there were 40 male embryos (48.2%) and 43 female embryos (51.8%). Sex of 31 embryos was determined using both SRY and amelogenin. Among those, 17 embryos were determined as having identical sex, while 1 embryo was determined as having different sex, and the sex of 11 and 2 embryos were determined only by amelogenin or SRY primers, respectively. In conclusion, the success of determining the sex of embryos by PCR was relatively high. Using amelogenin primer for PCR tends to be more efficient than SRY primer in determining the sex. Slightly higher ratio of female embryos was different from previous years and the cause for the difference may require further investigation.

In Hymenoptera, thanks to its haplodiploid sex determination, arrhenotokous parasitoid females are able to control offspring sex ratio by determining whether to use sperm or not at the time of oviposition. However, the offspring sex ratio may also be influenced by the mating behavior of a male. When a male searches females, he will have more chances to encounter with other males in a high male density population than low male density population. If the male is competitive, the male can find females faster and may have longer copulation time, and eventually transfer more sperm than other males. In this study, we investigated mate searching time, copulation duration and offspring sex ratio as a function of the male density. Although the results show difference between searching time and copulation duration, they are not statistically significant. We will discuss the statistical consequence, male density dependent offspring sex ratio and its evolutionary implications.

목적: 본 연구는 우리나라 성인의 건강형평성 주요 척도에 따른 백내장을 분석함으로써 눈 건강 형평성을 평가하고자 하였다. 방법: 국민건강영양조사(2009) 안검진 조사 데이터를 이용하여 무수정체안을 제외한 만 20세 이상의성인7,412명을 대상으로 소득수준, 교육수준, 직업, 지역에 따른 백내장의 유병률 및 오즈비를 분석하였다. 백내장은 안과전문의가 slit-lamp를 이용하여 검사하였다. 건강형평성 주요 척도에 따른 유병률은 t-검정 및 x² 검정하였고, 오즈비(odds ratio)는 로지스틱 회귀분석을 이용하였으며, 유의수준은 0.05로 PASW18.0을 사용하여 분석하였다. 결과: 백내장의 표준화 유병률은 26.4%이었다, 유병률은 가구소득‘하’에서41.2%, ‘초졸 이하’59.9%.‘무직’53.9%,‘도시지역’62.8%이었다. 건강형평성 주요 척도에 따른 백내장의 오즈비는 50세 이상군에서 가구소득이 ‘하’일 때 2.60(CI, 196-344), ‘무직군’일 때 2.33(CI, 1.49-3.34), 농촌지역에서 1.24(CI, 0.99-1.56)로 높게 나타났다. 20-49세군은 ‘초졸 이하’에서 5.48(CI, 2.71-11.06)이었고, ‘농림어업 숙련 종사지군’에서 .33(CI, 1.37-8.10)으로 높았다. 농촌지역에서 가구소득이 ‘하’일 때 오즈비는 2.33(CI, 1.35-3.69), ‘초졸 이하’일 때 2.03(CI, 0.97-4.26), ‘단순노무 종사지군’에서 1.28(CI, 0.52-3.14)로 도시지역에 비해 높았다. 여자의 경우 가구소득이‘하’에서 1.60(CI, 1.12-2.30), ‘초졸 이하’에서 1.79(CI, 1.09-2.92)로 남자에 비해 높게 나타났다. 결론: 낮은 사회경제적 상태에서 백내장의 유병률과 오즈비가 증가하여 우리나라 성인의 눈 건강 불평등이 존재하였으며, 이를 위해 저소득층을 위한 종합적인 일차안보건의료정책이 필요하다. 또한 외국의 안보건정책과의 비교를 통해 기존의 치료 위주의 보건정책보다는 예방과 교육 중심의 보건정책의 개발이 요구된다.

In mammals, the meiosis division in testes produces equal numbers of two different types of gametes: X chromosome-bearing sperm (X-spermatozoa) and Y chromosomebearing sperm (Y-spermatozoa), which have equal potential to fertilize the oocytes. Therefore, the expected 1: 1 sex ratio is observed. However, under some conditions like endocrine disruptors (EDs) exposure the sex ratio is deviated than the expected with more males or more females. And recently many hypotheses have been postulated to explain the mechanism of sex ratio deviation; however none of them introduced a proven experimental explanation. To solve this enigma, we hypothesized that the differences between X- and Y-spermatozoa survivability under specific conditions due to differences in their chromosome contents are the key leading to the sex ratio alteration. To examine our hypothesis, we combined two techniques; first, hypo-osmotic swelling (HOS) test that was applied to test viability of spermatozoa and second, fluorescence in situ hybridization that was applied on HOS-treated spermatozoa to define sex chromosome composition. In the present study, human spermatozoa were incubated with a group of EDs represent a widespread chemicals in the environment bisphenol A (BPA, 100 μM), nonylphenol (NP, 10 μg/ml), 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, 2.5 μg/ml), genistein (Gen, 100 μM), and the following pesticides, dibromochloropropane (DBCP, 10 μg/ml), atrazine (Atraz, 500 μM), and diazinone (Diaz, 500 μM) for 6 hr at 37℃ in 5% CO2. Then, the viability of spermatozoa and their sex chromosome contents were evaluated simultaneously. Among seven chemicals studied only four chemicals (Atraz, DBCP, TCDD, and Diaz) significantly decreased Y-sperm viability when compared to those of X-spermatozoa in the same treatment group and viability of Y-spermatozoa when compared to those in the negative and positive (DMSO) control groups (p<0.05). Also, in these four treatment groups the sex ratio of live sperm population was significantly lowered compared to the control groups (p<0.05). Otherwise, Gen, BPA, and NP did not show any significant effect on viability of Yspermatozoa or decreasing sex ratio in live sperm population as compared to the control groups. It has been proven that TCDD, DBCP, and the pesticides decrease the sex ratio, but the same effect was not observed in case of Gen, BPA, and NP. From the present findings, there is no doubt that the EDs may alter sex ratio via decreasing Y-spermatozoa viability.

The α-proteobacterium Wolbachia is maternally inherited and is known to induce reproductive distortions in a wide range of insect taxa such as cytoplasmic incompatibility, feminization, male killing and parthenogenesis (PI). When a female is infected with PI-Wolbachia, she does not need a male to produce female offspring, because the female can produce female offspring via gamete duplication without the aid of sperm. However, in the parasitoid wasp Trichogramma kaykai species, Wolbachia infected parthenogenetic females still produce a fraction of male offspring. Offspring sex ratio for 10 days are different according to each T. kaykai isofemale line that is infected with PI- Wolbachia. This may be caused by complex interactions between Wolbachia and the host genetic backgrounds on converting sex of infected eggs.

The α-proteobacterium Wolbachia pipientis infects a wide range of arthropods and filarial nematodes. Wolbachia is maternally inherited and is known to induce reproductive anomalies such as cytoplasmic incompatibility, feminization, male killing and parthenogenesis induction (PI). Trichogramma kaykai is a tiny wasp that parasitizes on lepidopteran eggs. When a female of the wasp is infected with PI-Wolbachia, the female produces female offspring via gamete duplication without the aid of sperm. As she ages, however, the fraction of male offspring increases. In this study, we investigated the effect of host genetic background on the expression of sex ratio between isofemale lines. Virgin females of six isofemale lines were allowed to lay eggs individually for 10 days. There was the positive relationship between female age and the offspring sex ratio. Furthermore, the sex ratio was significantly different among isofemale lines, implying that the host genetic background had an effect on the sex ratio. Based on the results, evolution of symbiosis in terms of sex ratio and future experimental design are discussed.

Effects of host density and refuge on the sex ratio of progeny of hymenopterous parasitoids was tested with Bracon hebetor Say parasitizing Plodia interpunctella (Hübner). The overall sex ratio (male/total) of progeny produced per female with and without refuge was estimated to be 0.49 and 0.41, respectively. Regardless of refuge, the sex ratio decreased as host density increased. But, at host density of 128 with refuge the sex ratio was significantly lower than that without regfuge (t=-2.17, df=24; P=0.040). The number of pupae per host larva with refuge was similar to that without refuge at the host densities tested (t=-0.10, df=53.4; P=0.921). The number of attacked host larvae showed significantly different at all host densities with and without refuge (t=-3.33, df=209; P=0.001).

Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

This study was carried out to collect the basic data about gestation lengths and offspring's birth weights and sex ratio of the dairy recipients transferred with Hanwoo IVF embryos. Blastocysts cultured for days were transferred to 96 and 167 heads for the basic data about gestation length and offspring's birth weight and sex ratio of the dairy recipients, respectively. The gestation lengths of the dairy recipients transferred with Hanwoo IVF embryos were () and () days in male and female of the offspring, respectively. The gestation lengths of the recipients were , , and days in spring, summer, autumn and winter of the calving season, respectively, and were significantly different among the calving season (p<0.05). The birth weights of male and female calves were () and ( kg in offsprings of the dairy recipients transferred with Hanwoo IVF embryos, respectively. The sex ratio was 90.7 in the offsprings of the dairy recipients transferred with Hanwoo IVF embryos.

The paternal sex ratio (PSR) chromosome is considered as an extremely selfish genetic element. It has only been found in the two hymenopteran insects- Nasonia and Trichogramma- with haplodiploid sex determination. When an egg is fertilized by sperm bearing PSR, the paternal genome is destroyed by PSR soon after fertilization resulting in haploid restoration and the egg develops into a male with only the maternal genome and PSR itself. Recently PSR is paid much attention, since it may be used for controlling haplodiploid pests. PSR can be successfully transferred from its natural host, T. kaykai to the novel host, T. deion. In the two hosts another sex ratio distorter, Wolbachia, is found. Wolbachia is a cytoplasmically inherited bacterium that induces parthenogenesis in this genus resulting in female offspring production without fertilization. The transmission efficiency of PSR in T. deion is lower than that in T. kaykai and is negatively influenced by the Wolbachia infection. The results show that 1) there is a negative host genetic background effect on the transmission of PSR in the novel host, 2) the transmission efficiency becomes even lower, when PSR males are infected with Wolbachia. The results imply that complex interactions among the bacterium, PSR and the species specific genetic background.

쌀바구미좀벌은 쌀바구미의 3영유충과 4영유충에 생난, 기생하였으며, 4영유충에 대해 현저한 선호성을 보였다. 기주가 4영유충일 때의 성비가 3영유충일 때에 비해 유의하게 높아서 생난시 암컷에 의해 인식되는 기주의 크기에 따라 좀벌의 성비가 조걸됨을 암시하였다.