The mammary gland tumor (MGT) is the most common neoplasia in intact female dogs. Of these, 50% are malignant and metastasis to the other sites are often occurred. Therefore, it is very important for decision of treatment plan and prognosis to differentiate benign tumor from malignancies. Calcification of MGT is a very important imaging finding. The purpose of this study was to investigate the radiological and computed tomographic images of the MGT and the morphology and distribution of calcifications in the MGT using the Breast Imaging Reporting and Data System classification. A total of 42 dogs with MGT were included in this study. The dogs were divided into two groups into benign and malignant groups based upon histologic or cytologic results. The appearance of calcification in the tumor on radiographs and CT images was analyzed for the HU value of pre- and post-contrast injection, margin, surface, and shape of the tumor and the lymph node abnormalities. On radiographs, the positive predictive value of malignant and benign tumors was 72.72 and 85.71%, respectively. On CT examinations, the positive predictive value of malignant and benign tumors was the same value of 83.33%. The maximum diameter of the tumor and the presence of abnormal lymph nodes on CT images showed a strong correlation with malignancies. Therefore, it is thought that radiographs and CT provide useful information for evaluating MGT in dogs.

The mammary gland is a complex organ, made up of various cell types that work together for mil synthesis. A previous study had established a clonal cell line from primary bovine mammary alveolar cells (MAC-T) for the study of bovine milk production and synthesis. In this study, we transplanted MAC-T bovine alveolar cell line to BALB/C nude mice for regeneration of bovine mammary gland alveolar ducts. The MAC-T cells were suspended with matrigel and injected into the dorsal tissue of 8 weeks old male BALB/C nude mice. After 6 weeks, the injected cells were showed typical morphology of the tubuloalveolar female glands by histological analysis. It was made the branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14 and CK18 positive cells but not in the non-transplanted MAC-T cells. These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14 and CK18 positive MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.

Effectiveness of transgene transfer into genome is crucially concerned in mass production of the bio-pharmaceuticals using genetically modified transgenic animals as a bioreactor. Recently, the mammary gland has been considered as a potential bioreactor for the mass production of the bio-pharmaceuticals, which appears to be capable of appropriate post-translational modifications of recombinant proteins. The mammary gland tissue specific vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals. In this study, to minimize physiological disturbance caused by constitutive over-expression of the exogenous gene, we constructed new retrovirus vector system designed for mammary gland-specific expression of the hEPO gene. Using piggyBac vector system, we designed to express hEPO gene under the control of mammary gland tissue specific and lactogenic hormonal inducible goat β-casein or mouse Whey Acidic Protein (mWAP) promoter. Inducible expression of the hEPO gene was confirmed using RT-PCR and ELISA in the mouse mammary gland cells treated with lactogenic hormone. We expect the vector system may optimize production efficiency of transgenic animal and reduce the risk of global expression of transgene.

The insulin-like growth factor (IGF) pathway is a key signal transduction pathway involved in cell proliferation, migration, and apoptosis. In dairy cows, IGF family proteins and binding receptors, including their intracellular binding partners, regulate mammary gland development. IGFs and IGF receptor interactions in mammary glands influence the early stages of mammogenesis, i.e., mammary ductal genesis until puberty. The IGF pathway includes three major components, IGFs (such as IGF-I, IGF-II, and insulin), their specific receptors, and their high-affinity binding partners (IGF binding proteins [IGFBPs]; i.e., IGFBP1–6), including specific proteases for each IGFBP. Additionally, IGFs and IGFBP interactions are critical for the bioactivities of various intracellular mechanisms, including cell proliferation, migration, and apoptosis. Notably, the interactions between IGFs and IGFBPs in the IGF pathway have been difficult to characterize during specific stages of bovine mammary gland development. In this review, we aim to describe the role of the interaction between IGFs and IGFBPs in overall mammary gland development in dairy cows.

태반이나 생식소 등 시상하부 이외의 조직에서도 gonadotropin releasing hormone(GnRH)과 그 수용체가 발현되어 조직 특이적인 기능을 담당함은 잘 알려진 사실이다. 최근 GnRH와 그 수용체 유전자가 흰쥐 유선에서도 발현됨이 증명되었고, LH -와 -subunit와 LH 수용체에 대한 전사체 역시 흰쥐 유선에 존재함이 확인되었다 본 연구는 흰쥐 유선 LH의 발현과 유선의 분화과정 간의 상관관계를 조사하기 위해서 생식주기, 임신,

Gonadotropin-releasing hormone (GnRH)과 그 수용체가 흰쥐의 난소, 정소, 자궁, 태 반 그리고 유선 등의 생식기관에서 발현됨이 알려져 있다. 더욱이, 뇌하수체 전엽에 작용하는 GnRH의 표적 산물로 알려진 luteinizing hormone (LH)이 흰쥐 생식소에서도 발현됨이 알려졌는데, 이는 생식소 내에 GnRH-LH로 이루어진 국부 회로 (local circuit)가 존재함을 시사하는 것이다 본 연구는 LH와 그 수용