title: KIT receptor-positive cells in the bovine corpus luteum are primarily theca-derived small luteal cells.
abstract: The tyrosine kinase KIT receptor, the protooncogene CD117, plays a key role in growth and maturation of oocytes and follicles. Relevant data are sparse for the corpus luteum (CL). We first confirmed the presence of KIT mRNA and KIT protein in bovine CL homogenates. We then localized KIT-positive (KIT+) cells in CL sections by immunohistochemistry. At the CL stage of early development, the former theca transforming into capsule/septa showed a strong band-like KIT+ immunoresponse. In addition, CD45+ leukocytes in septa included subpopulations of CD45+/KIT+ and CD14+/KIT+ leukocytes as validated by double immunofluorescence localization. At the early secretory stage, KIT+ cells appeared within the septa/capsule region and in the periphery of the CL parenchyma, there forming a complex network. This was separate from the capillary bed as determined by double staining for CD117 and FVIII-related endothelial cell antigen (FVIIIr). The KIT+ network coincided with cells positive for cytochrome P450 17alpha-hydroxylase, a thecal cell-specific enzyme. The late secretory stage was defined by an advanced manifestation of the KIT+ network in the CL periphery. At the stage of regression, the KIT+ network was absent. The CL of pregnancy expressed high levels of KIT mRNA and KIT protein uniformly throughout pregnancy. The KIT+ immunolocalization revealed small fibroblast-like cells, luteal cells with granules, and clusters of large luteal cells with staining of the cell membrane. We conclude that a majority of KIT+ cells in the bovine CL are primarily theca-derived small luteal cells, and that a minority represent KIT+ leukocytes, in some cases KIT+ monocytes.
authors: Institute of Anatomy, University of Leipzig, Liebigstrasse 13, D-04103 Leipzig, Germany. spanelb@medizin.uni-leipzig.de
authors: Katharina
authors: K
authors: Spanel-Borowski
authors: Kristina
authors: K
authors: Sass
authors: Sabine
authors: S
authors: Löffler
authors: Elke
authors: E
authors: Brylla
authors: Michiharu
authors: M
authors: Sakurai
authors: Albert M
authors: AM
authors: Ricken
mesh_terms: D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000166:cytology*; D003340:Corpus Luteum Maintenance / Q000502:physiology*; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D007962:Leukocytes / Q000737:chemistry; D008184:Luteal Cells / Q000737:chemistry*; D009000:Monocytes / Q000737:chemistry; D011247:Pregnancy; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019089:Stem Cell Factor / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit