Echinoids have an endoskeletal system which is ideal for studying calcified structures such as development of vertebrate skeletons. However, understanding echinoid skeletal (test) growth has proven challenging to analyse solely on the basis of any one approach or process. Therefore, theoretical models have been developed to understand growth and form of echinoid tests. Herein, Holotestoid, a computational model of echinoid test growth is described. The model incorporates mathematical principles (e.g., close-packing), physical principles (e.g., interface between coalescing bubbles) and biological processes (e.g., echinoid ontogenic processes). It is the first computational model that emulates all five ontogenic processes involved in test growth (plate growth, plate addition, plate interaction, plate gapping, and visceral growth) using a geometrical representation and three analogies (coalescing bubble, circle-packing, and catenary chains). The emulated processes are used to predict plate size, plate shape, and test shape. The results from the simulations of the growth zones show that the ambulacral column angle (e.g., for A. punctulata α_am= 22° and for S. franciscanus α_am = 32°) is a crucial parameter that distinguishes between species when varied. The. comparison of simulated data with those from real specimens yielded high accuracies, thereby validating the model. The combination of the simulated processes produced patterns mimicking real biological specimens. The model was further used to investigate the test morphological disparity observed among echinoids, specifically between. regular echinoid (sea urchin) tests and irregular echinoid (sand dollar) tests. Both exhibit morphological similarities as imagines, however, they develop different test morphologies as adults. Thus, Holotestoid was used to explore the influence of each parameter on test height-todiameter ratio (h:d). The results showed that both ambulacral column widening and increase in total plate number cause the test h:d to decrease thereby leading to test flattening. Whereas the absolute size of the apical system and peristome does not influence test h:d, however, their growth with respect to column length caused an increase in the test h:d. These results provide an explanation of how the different test shapes were obtained. / Thesis / Doctor of Philosophy (PhD)

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20979号 / 医博第4325号 / 新制||医||1026(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 妻木 範行, 教授 戸口田 淳也, 教授 柳田 素子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21660号 / 医博第4466号 / 新制||医||1035(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 柳田 素子, 教授 滝田 順子, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

This study analyzed skeletal development, body condition, and total body fat development of growing heifers. A total of 144 female primiparous Holstein cattle from four commercial dairy farms with different degrees of stillbirth rates were examined during the rearing period. This included measurements in body condition, fat tissue, metabolic, and endocrine factors. Pelvic measurements and the sacrum height were analyzed to assess skeletal development. The body condition was classified via body condition scoring, bioelectrical impedance analysis (BIA), back fat thickness measurements, and the body mass. For the first time, BIA was used as an appropriate method to evaluate the fat tissue content of cattle throughout the rearing period. This analysis technique can be performed on heifers aged 8–15 months. Throughout that period, the fat content decreased while the skeletal development increased. In addition, high free fatty acid concentrations in serum of the animals with high frame development were found, supporting our hypothesis that stored energy of body fat deposits is used for skeletal growth. Furthermore, we were able to demonstrate complex endocrine relationships between fat metabolism and skeletal growth by using specific markers, such as leptin, insulin growth factor-1 (IGF-1), and estradiol (E2). Food analysis showed high crude protein (CP) levels in the total mixed ration above recommendation for daily protein intake of all farms. However, there was a positive correlation between CP and the body frame measurements in our study. In summary, we established a novel regression formula for BIA analysis (“BIA-Heine”) in heifers to evaluate the body composition throughout different ages and physiological stages in the development of heifers. This special formula allows the evaluation of fat tissue without a whole-body analysis and therefore provides an innovative technique for animal welfare support.