No description available.

The objective of this experiment was to examine the effects of varying the interval from follicular wave emergence to progestin removal on follicular dynamics and the synchrony of estrus. The experimental design was a 2x2x2 factorial with GnRH or estradiol-17 beta (E2) + progesterone (P4), controlled internal drug-releasing device (CIDR) treatment duration, and PG or saline treatment as main effects. Cycling, Angus cows (n=49), on d 6 to 8 of the estrous cycle, were randomly assigned to receive a CIDR treatment for 7 or 9 d. Approximately half of the cows from each CIDR group received either GnRH (100 mcg) or E2+P4 (1 mg E2 + 100 mg P4) at CIDR insertion. Cows in GnRH or E2+P4 groups were further divided into those that received PG (37.5 mg) or saline at CIDR insertion. All cows received PG (25 mg) 1 d prior to CIDR removal. The interval from follicular wave emergence to CIDR removal was longer for cows treated with GnRH (6.6 d) or a CIDR for 9 d (6.5 d) compared to those treated with E2+P4 (4.7 d) or a 7-d CIDR (4.8 d) (P < 0.05). Cows treated with PG or GnRH at CIDR insertion or a 9-d CIDR had a larger dominant follicle (DF) at CIDR removal than those treated with saline, E2+P4, or a 7-d CIDR. (P < 0.07). Altering the interval from wave emergence to progestin removal created differences in size of the DF at CIDR removal but did not affect the synchrony of estrus. / Master of Science

Yes / The cutaneous healing response has evolved to occur rapidly, in order to minimize infection and to re‐establish epithelial homeostasis. Rapid healing is achieved through complex coordination of multiple cell types, which importantly includes specific cell populations within the hair follicle (HF). Under physiological conditions, the epithelial compartments of HF and interfollicular epidermis remain discrete, with K15+ve bulge stem cells contributing progeny for HF reconstruction during the hair cycle and as a basis for hair shaft production during anagen. Only upon wounding do HF cells migrate from the follicle to contribute to the neo‐epidermis. However, the identity of the first‐responding cells, and in particular whether this process involves a direct contribution of K15+ve bulge cells to the early stage of epidermal wound repair remains unclear. Here we demonstrate that epidermal injury in murine skin does not induce bulge activation during early epidermal wound repair. Specifically, bulge cells of uninjured HFs neither proliferate nor appear to migrate out of the bulge niche upon epidermal wounding. In support of these observations, Diphtheria toxin‐mediated partial ablation of K15+ve bulge cells fails to delay wound healing. Our data suggest that bulge cells only respond to epidermal wounding during later stages of repair. We discuss that this response may have evolved as a protective safeguarding mechanism against bulge stem cell exhaust and tumorigenesis. / BBSRC.

Master of Science / Department of Animal Sciences and Industry / Timothy G. Rozell / Timothy G. Rozell / An increase in pre-mating dietary energy positively influences ovulation and lambing rates, and this practice is known as nutritional flushing. The mechanisms of flushing, however, are still unknown. Increasing dietary energy approximately two weeks before breeding likely increases the production of insulin-like growth factor I (IGF-I) within the ovary, which stimulates the synthesis of follicle stimulating hormone receptor (FSHR). Several alternatively spliced transcripts of the FSHR have been identified in sheep. Each variant form is believed to be produced according to the stage of follicle development. This study was carried out to evaluate expression patterns of the FSHR variant forms (FSHR-1, FSHR-2 and FSHR-3) in the sheep ovary in response to different flushing diets. For this experiment, yearling Rambouillet ewes (n=93) were allocated among 6 different energy type treatment diets, either prairie or alfalfa hay based, for at least two weeks in combination with the insertion of a controlled internal drug releasing device (CIDR). Two of the treatment groups had commercially available block supplements provided and two had rolled corn supplemented. Mid-ventral laparotomy was performed on each ewe 3.5 to 4 days after CIDR removal. Follicles 4 mm and greater were aspirated and categorized as either medium (M; 4 to 6 mm) or large (L; > 6 mm). Total RNA was extracted from granulosa cells (GC) and reverse transcribed followed by qPCR of the resulting cDNA using specifically designed primer sets for each variant of the FSHR and for the LH receptor. Changes in live weight were different (P < 0.01) between treatment diets but there were no statistical differences for NEFA concentrations between any of the treatments nor were there differences for body condition (mean = 3.0) or lambing rate. Therefore, it is likely a flushing response did not occur in this study. Expression of FSHR-1was different between M and L follicles (P < 0.01) and tended to be different for ewes fed alfalfa hay (P = 0.05). Overall mean expression of FSHR-3 was greater than expression of FSHR-1 or FSHR-2 (P < 0.01), although there was no difference between M and L follicles, or between treatment diets. The concentration of estradiol in follicular fluid was not different between the treatment diets or follicle sizes nor was expression of lutenizing hormone receptor (LHR), indicating that follicles were similar developmentally. The FSHR-1 form seemed to be the variant most likely to be involved in later stages of follicular development, and is potentially involved in follicle rescue. For all follicles, FSHR-3 was the more highly expressed form of the FSHR and may likely be essential throughout antral follicle development. Further research is required to determine the exact mechanism whereby initial energy status of ewes seems critical for the increased ovulation rate that occurs after energy supplementation (i.e. the flushing response).

Much has been improved in the basic and applied aspect of female reproduction after understanding of the wave-like developmental pattern of follicles ¡Ý4 mm. However, it is speculated that the understanding of the developmental pattern of small follicles <4 mm may bring about efficient management of ovarian functions for essential reproductive interventions. Present studies were therefore, carried out to characterize the developmental pattern of 1-3 mm follicles in cattle using ultrasonography and to validate a method to histologically characterize the developmental pattern of follicles <1 mm using non-serial data. Transrectal ultrasonography was used once daily (n=18 Hereford-cross heifers) to examine changes in the diameter of follicles ¡Ý1 mm for one interovulatory interval (IOI), as well as every 6 h (n = 9 Hereford-cross cows) from 5 to 13 days after ovulation to encompass emergence of Wave 2. A periodic shift in the peak number (P < 0.05) of 1-3 mm and ¡Ý4 mm follicles and a significant inverse relationship (P < 0.05) between them suggested a wave-like developmental pattern. The number of 1-3 mm follicles detected in anovulatory waves did not differ (P = 0.53) between 2- versus 3-wave IOIs. A difference (P < 0.05) was noticed between anovulatory and ovulatory waves in 3-wave IOIs but not (P = 0.63) in 2-wave IOIs. The future dominant follicle was identified at 1 mm and was found to emerge 6-12 h earlier than the largest subordinate follicle (P < 0.01). Emergence of the future dominant (r = 0.71) and 1st subordinate (r = 0.78) follicles was temporally associated (P < 0.05) with a rise in circulating concentrations of FSH. <p> The developmental pattern of follicles not detectable by ultrasonography (<1 mm) may be assessed histologically by examining the ovaries from different animals on different days (i.e., non-serial method) using follicle diameter or number profiles. A data set (n = 56 heifers) of follicles ¡Ý4 mm was tabulated in a serial (same set of heifers each day; n = 7/day, N = 7) and non-serial (different set of heifers each day; n = 7/day, N = 56) manner for number and diameter profiles around emergence of the first follicular wave. Profiling of serial and non-serial data (serial and non-serial methods) revealed a change in the number of follicles (4-5 mm, 6-8 mm, ¡Ý9 mm) over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.28). Similarly, the diameter of the dominant and first 2 subordinate follicles changed over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.06), indicating that non-serial data provide wave-like profile of follicles. <p> In conclusion, the hypothesis that follicles 1-3 mm develop in a wave-like manner was supported, and a new non-serial method was validated for the study of follicle dynamics using non-serial (e.g. histologic) data.

Much has been improved in the basic and applied aspect of female reproduction after understanding of the wave-like developmental pattern of follicles ¡Ý4 mm. However, it is speculated that the understanding of the developmental pattern of small follicles <4 mm may bring about efficient management of ovarian functions for essential reproductive interventions. Present studies were therefore, carried out to characterize the developmental pattern of 1-3 mm follicles in cattle using ultrasonography and to validate a method to histologically characterize the developmental pattern of follicles <1 mm using non-serial data. Transrectal ultrasonography was used once daily (n=18 Hereford-cross heifers) to examine changes in the diameter of follicles ¡Ý1 mm for one interovulatory interval (IOI), as well as every 6 h (n = 9 Hereford-cross cows) from 5 to 13 days after ovulation to encompass emergence of Wave 2. A periodic shift in the peak number (P < 0.05) of 1-3 mm and ¡Ý4 mm follicles and a significant inverse relationship (P < 0.05) between them suggested a wave-like developmental pattern. The number of 1-3 mm follicles detected in anovulatory waves did not differ (P = 0.53) between 2- versus 3-wave IOIs. A difference (P < 0.05) was noticed between anovulatory and ovulatory waves in 3-wave IOIs but not (P = 0.63) in 2-wave IOIs. The future dominant follicle was identified at 1 mm and was found to emerge 6-12 h earlier than the largest subordinate follicle (P < 0.01). Emergence of the future dominant (r = 0.71) and 1st subordinate (r = 0.78) follicles was temporally associated (P < 0.05) with a rise in circulating concentrations of FSH. <p> The developmental pattern of follicles not detectable by ultrasonography (<1 mm) may be assessed histologically by examining the ovaries from different animals on different days (i.e., non-serial method) using follicle diameter or number profiles. A data set (n = 56 heifers) of follicles ¡Ý4 mm was tabulated in a serial (same set of heifers each day; n = 7/day, N = 7) and non-serial (different set of heifers each day; n = 7/day, N = 56) manner for number and diameter profiles around emergence of the first follicular wave. Profiling of serial and non-serial data (serial and non-serial methods) revealed a change in the number of follicles (4-5 mm, 6-8 mm, ¡Ý9 mm) over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.28). Similarly, the diameter of the dominant and first 2 subordinate follicles changed over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.06), indicating that non-serial data provide wave-like profile of follicles. <p> In conclusion, the hypothesis that follicles 1-3 mm develop in a wave-like manner was supported, and a new non-serial method was validated for the study of follicle dynamics using non-serial (e.g. histologic) data.

Primary wool follicles are initiated in the skin of sheep foetuses at approximately day 50 of gestation as the result of complex reciprocal molecular interactions between the mesenchyme and overlying epithelium. The lifetime wool production potential and fibre diameter of the Merino sheep is dependent on the total number of follicles initiated in utero. Understanding the molecular events that surround primary wool follicle initiation may provide approaches to enhance or manipulate this process in order to maximise the profitability of wool production enterprises. In order to study the morphological and molecular changes occurring during early wool follicle development, a foetal skin series spanning primary follicle initiation was generated. Foetal skin was sampled from the shoulder, midside and rump of four foetuses at 8 time points between day 43 and day 68 of gestation. Histological characterisation of the shoulder skin samples revealed that primary epidermal placodes emerged at around day 53, dermal condensates were visible from day 57 and downgrowth of the follicle began at day 68. An equation relating age of the foetus (day of gestation post AI) and crown-rump length, specific to Merino foetuses, was developed for use in future studies of this nature. Molecular markers of fibroblast migration, epidermal and dermal stem cells and cell proliferation were selected to test the hypothesis that dermal condensates are initiated at discrete sites beneath the epidermis as a result of a combination of migration and arrangement of multipotent pre-papilla cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis of RAC1 and RHOa (migration markers), β1-integrin and alkaline phosphatase (stem cell markers), proliferative nuclear cell antigen and cyclinB1 (proliferation markers), patched-1, selected tumor necrosis factor (TNF) signalling molecules and eleven reference genes was conducted using midside and rump skin samples from each of four foetuses from the 8 time points. geNorm analysis of the reference and target genes revealed that the migration markers RAC1 and RHOa along with GAPDH were the most stably expressed genes in this sample series. Significant changes in mRNA expression were detected for β1-integrin, alkaline phosphatase, patched-1 and the TNF members EDA, EDAR, TROY and TRAF6. Many of these significant differences in expression coincided with key morphological events. Significant differences in expression were also detected between the midside and rump samples for numerous transcripts. Laser capture microdissection (LCM) was implemented for analysis of the target transcripts within particular structures of foetal sheep skin. Frozen tissue sectioning, staining, LCM, RNA extraction and cDNA synthesis were optimised for qRT-PCR analysis of endogenous controls and selected TNF transcripts. Several RNA extraction methods and reverse transcription approaches were trialled to ensure optimum extraction and reverse transcription efficiency for this tissue type. Exogenous mRNA transcripts were also incorporated prior to RNA extraction and reverse transcription to track reaction efficiency between samples. A comparison of different slide types revealed that laser pressure catapulting from membrane slides was an absolute requirement for foetal skin tissue studies. Follicle regions (including the epidermal placode and dermal condensate) and the adjacent non-follicle regions were laser captured from foetal skin, and the mRNA expression levels of patched-1 and selected TNF members was compared. Preliminary qRT-PCR analysis using this technique revealed that EDAR, TROY and PTCH1 mRNA levels were higher in the follicle regions than the non-follicle regions. The TNF signalling pathway appears to play an important role in primary wool follicle initiation and patterning at different sites on the body. Spatial differences in expression of some of these regulators may be involved in initiating different types of follicles. The molecular events surrounding primary wool follicle initiation also show a high degree of conservation between sheep, humans, and mice. Considering the high degree of DNA sequence conservation as well as the histological, signalling and cycling similarities between sheep and humans, sheep may represent a better model for the study of human hair follicle initiation and disease than the currently used mice and rat models. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1523639 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2010

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23570号 / 医博第4784号 / 新制||医||1054(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 近藤 玄, 教授 滝田 順子, 教授 篠原 隆司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Yes / Pattern Hair Loss (PHL) is a chronic regressive condition of the scalp, where follicular miniaturisation and decreased scalp hair coverage occurs in affected areas. In all PHL cases there is a measurable progressive shortening of the terminal hair growth duration, along with reduced linear growth rates. In both genders, PHL initially shows an increase in short telogen hairs ≤30mm in length, reflecting a cycle completion of under six months in affected terminal hair follicles. To understand the miniaturisation process, we re-examine the dynamics of miniaturisation and ask the question, 'why do miniaturised hair follicles resist treatment?' In the light of recent developments in relation to hair regeneration, we looked back in the older literature for helpful clues 'lost to time' and reprise a 1978 Hermann Pinkus observation of an array of elastin deposits beneath the dermal papilla following subsequent anagen/telogen transitions in male balding, originally described by Arao and Perkins who concluded that these changes provide a "morphologic marker of the entire biologic process in the balding scalp". Thus, we have reviewed the role of the elastin-like bodies in hair pathology and we propose that alterations in elastin architecture may contribute to the failure of vellus-like hair reverting back to their terminal status and may indicate a new area for therapeutic intervention.