Skin follicle development in Cheviot × Dorset Horn cross foetuses

1975 ◽  
Vol 84 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Marjorie B. Derbyshire
Keyword(s):  
Follicle Development ◽  
Secondary Follicle ◽  
Skin Samples

SUMMARYSkin samples were used to evaluate the developing skin follicle population of Cheviot × Dorset Horn cross foetuses. The follicle population was studied from the first appearance of skin follicles (55 days' gestation) to the end of gestation. The pattern of development of primary and secondary follicles is described, and compared with the data available for other breeds. The occurrence of secondary follicle branching, previously confirmed only in the Merino, is described, and the ‘prenatal check’, an important feature of follicle development which had not previously been investigated in prenatal studies, is briefly discussed.

Effect of egg transfer on the skin follicles and birthcoats of Finnish Landrace and Soay lambs

1974 ◽  
Vol 82 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Marca Burns ◽  
M. L. Ryder
Keyword(s):  
Fibre Type ◽  
Opposite Effect ◽  
Fibre Diameter ◽  
Follicle Development ◽  
Direct Effects ◽  
Hair Density ◽  
Maternal Environment ◽  
Secondary Follicle ◽  
Wide Range ◽  
Skin Samples

SummaryThe birthcoats of Finnish Landrace lambs showed a wide range of halo-hair grades but all had strongly checked fibre type arrays, which were either Plain or Valley. Transfer to Welsh Mountain dams reduced the effect of prenatal check, giving fewer sickle fibres and increased halo-hair and/or super sickle A percentage. Transfer to Border Leicester tended to have the opposite effect. Fibre diameter measurements made on skin samples indicated an increase in primary fibre diameter in transfers into Welsh dams, but no difference in transfers into the Border Leicester.All Soay samples had Grade VII halo-hair density and Plateau or Saddle arrays. Transfer of Soay eggs to Finnish Landrace ewes increased the percentage of sickle fibres mainly at the expense of hairy-tip curly-tips. Skin samples from the transferred Soays indicated reduced primary fibre medullation, and evidence of retarded secondary follicle development.Thus in both breeds the birthcoat changed slightly in the direction of that of the foster-dam. There was, however, no indication that increased prenatal check was associated with increased foetal size. It is therefore concluded that changes in birthcoat as a result of egg transfer are more probably due to direct effects of the maternal environment than to the effect of foetal size as previously postulated.

Wool follicle development in the New Zealand Romney and N type sheep. II. Follicle population density during foetal development

1958 ◽  
Vol 9 (1) ◽  
pp. 138 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Subsequent Development ◽  
The Body ◽  
Limiting Factor ◽  
Follicle Development ◽  
Primary Follicle ◽  
Foetal Development ◽  
Secondary Follicle ◽  
The Face

Quantitative aspects of follicle initiation and development have been studied in a series of N-type and New Zealand Romney foetuses. Density of the follicle population and ratios of secondary to primary follicles were examined on 13 positions of the body which covered the main wool-bearing areas, the face and head, and the limbs. Primary follicle development is initiated first on the head and limbs and throughout subsequent development these regions are most advanced. Primary follicle density reaches a maximum between 75 and 90 days of foetal age, after which it decreases as a result of skin growth. Secondary follicle initiation is more rapid on the wool-bearing areas of the body, and higher ratios of secondary to primary follicles are recorded from these regions. No real differences have been found between N-type and New Zealand Romney foetuses in population density of the different follicle types at any age or in the number of secondary follicles developed per primary follicle. The growth of larger primary fibres and follicles in N-type foetuses is not accompanied by, and does not result from, a lower density of primary follicles. There does not appear to be any marked relation between the decreasing density of primary follicles after 90 days of foetal age and the initiation of secondary follicle anlagen. This fact, and the absence of any differences in the number of secondary anlagen formed per primary follicle in N-types, suggest that crowding in N-types is not a limiting factor in the formation of secondary follicle anlagen.

scholarly journals Red LED light promotes hair follicle development to improve fibre quality in Su line Angora rabbit

2019 ◽  
Author(s):  
Feng Qin ◽  
Jing Wang ◽  
Le Shao ◽  
Xiaoqing Pan ◽  
Jie Yang ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Fibre Diameter ◽  
Follicle Development ◽  
Fibre Quality ◽  
Primary Follicle ◽  
Led Light ◽  
Secondary Follicle ◽  
Red Led ◽  
Wool Yield ◽  
Hair Follicle Development

Abstract Background: Light has crucial roles in animal physiological activities. This study aimed to investigate the effects of different colours of light-emitting diodes (LEDs) on rabbit fibre quality and hair follicle development. 50 three-month-old Su line Angora rabbits were randomly assigned to five groups. Treatment groups were exposed to same intensities of red, green and blue LED light under 16 h light:8 h dark photoperiod regimes. Control groups were exposed to white light and black. The trial spanned 73 days. Results: Results showed that LED colours exerted different effects on wool yield, fibre quality, hormones and hair follicle development. The wool yield of red group was higher than that of white, green and black groups (P<0.05). The shoulder fibre length of red group was higher than that of white and green groups (P<0.05). The coarse fibre diameter of white group was lower than that of green and black groups (P<0.05). The fibre diameter of red group was the lowest and was lower by 13.9% than that of control group (P>0.05). The coarse fibre ratio of green group was higher (13.31%) than that of red group (3.81%, P<0.05). The follicle groups of white, green and black groups consisted of 1 primary follicle associated with 3 or 4 secondary follicle groups and those of blue group consisted of 1 primary follicle associated with 5–10 secondary follicle groups. The follicle of red group consisted of numerous secondary follicles and a few primary follicles. In same magnification, the numbers of follicle groups of white, red, green, blue and black groups were 14.0, 16.5, 10.0, 11.67 and 11.0, respectively. The numbers of follicle groups of red and green groups significantly differed (P<0.05). Serum melatonin (MT) of red group was highest than that of white and green groups (P<0.01), higher than that of black group (P<0.05), serumTriiodothyronine (T 3 ) of red group was higher than that of white and black groups (P<0.05). Conclusions: Thus, the data reveal that red LED light can improve fibre quality, this may be due to red LED light which can enhance the secretion of melatonin to promote hair follicle development .

scholarly journals Inner Mongolian Cashmere Goat Secondary Follicle Development Regulation Research Based on mRNA-miRNA Co-analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wenjing Han ◽  
Feng Yang ◽  
Zhihong Wu ◽  
Fuqiang Guo ◽  
Junjie Zhang ◽  
...  
Keyword(s):  
Follicle Development ◽  
Cashmere Goat ◽  
Secondary Follicle ◽  
Development Regulation

Post-natal follicle development and fleece changes in two selection lines of Scottish Blackface sheep

1974 ◽  
Vol 18 (2) ◽  
pp. 169-177 ◽  
Author(s):  
M. L. Ryder
Keyword(s):  
Fibre Type ◽  
The Other ◽  
Control Line ◽  
Follicle Development ◽  
Control Groups ◽  
Fine Line ◽  
And Control ◽  
Skin Samples

SUMMARYFleece and skin samples were taken at intervals from birth to 86 days from Scottish Blackface lambs born into one line selected for hairiness, another for fineness and an unselected control line. The birthcoats in the Hairy line were longer than those in the Fine line, and had a predominance of Plateauo and Pi fibre type arrays, whereas P2 and P3 arrays predominated in the Fine line. The Hairy group had significantly more halo hairs and hairy-tip curly-tip fibres, but significantly fewer histerotrichs.Most secondary follicles had fibres by 56 days, and development appeared to be faster in the Control than in the other two groups. The Hairy and Control groups had consistently high percentages of primary medullation, whereas the Fine group had a peak at 14 days. The Fine group had consistently low secondary medullation, whereas it increased in the Hairy and Control lambs, apart from a set-back at 28 days.Up to 56 days the Fine group had no fibre shedding in the skin, and the Hairy group had most, although the incidence in any sample was less than 2%. There was more follicle inactivity at 86 days, and the Fine group then had most.

The effects of exogenous melatonin and prolactin on wool follicle development in ovine foetal skin grafts

1993 ◽  
Vol 44 (5) ◽  
pp. 993 ◽  
Author(s):  
CE McCloghry ◽  
DE Hollis ◽  
A Foldes ◽  
AJ Rintoul ◽  
P Baker ◽  
...  
Keyword(s):  
Nude Mice ◽  
Follicle Development ◽  
Skin Grafts ◽  
Epidermal Thickness ◽  
Exogenous Melatonin ◽  
Merino Sheep ◽  
Secondary Follicle ◽  
Wool Follicle

The fleece of the Merino sheep is composed predominantly of wool fibres grown from secondary wool follicles. This study investigates the effects of melatonin and prolactin on the development of secondarv follicles in grafted ovine foetal skin. Skin from day 85 ovine foetuses was grafted onto nude mice, developed for 40 days and then excised. Mice received either 30 8g prolactin ip mouse-1 day-1 (P), one melatonin implant (Regulin�) sc mouse -1 (M), commencing at grafting or no further treatment (C). Wool follicle density and development were assessed in grafted skin and compared with day 125 control foetal skin. Cuticle structure of graft fibres was also examined and compared with those of day 125 foetuses. Total follicle density and the rate of follicle initiation were reduced in the grafts compared with control foetal skin. Total follicle density did not vary significantly between treatments, but the number of derived secondary follicles was greater in grafts from mice receiving prolactin (group P). Follicles in grafted skin were larger, produced medullated fibres, and were not grouped, in comparison with follicles in the control foetal skin. Epidermal thickness was greater in grafts than in control foetal skin. The cuticle structure of graft fibres from all groups was similar to the control wool fibres. These findings indicate that prolactin, but not melatonin, may be involved in the regulation of derived secondary follicle development.

The development and structure of, and seasonal change in, the coat of some Wiltshire sheep

1969 ◽  
Vol 11 (4) ◽  
pp. 467-477 ◽  
Author(s):  
M. L. Ryder
Keyword(s):  
Seasonal Change ◽  
Seasonal Cycle ◽  
Follicle Development ◽  
Peak Period ◽  
Spring Equinox ◽  
Skin Samples

SUMMARYCoat and skin samples were taken monthly from three Wiltshire ewes for two years, and then fortnightly between the spring equinox and the autumn equinox of 1968.The fleece comprised kemp and wool, having a weight of 1·1 kg and a length of 50 mm. In summer all the primary fibres had a latticed medulla, and although the secondaries were smaller than the primaries, they were relatively coarse and often medullated, over one-third having a latticed medulla at the peak period. The overall mean S/P ratio was 3·5.Follicle development was studied in four lambs from birth to 84 days. Only 27% of the secondaries lacked fibres at birth, and all had fibres at 14 days. There was a trend of increasing medullation in the primary fibres. Shedding primary follicles were seen from birth onwards, and shedding secondaries from 28 days, although obvious casting of the birth coat did not begin until 84 days (at the beginning of June).There was a basic seasonal cycle of follicle activity starting in March and lasting until September; inactivity began in September, reached 100%, and continued at this level until March. Subsidiary cycles suspected from the monthly samples were confirmed by the fortnightly samples. Thus peaks of inactivity in June and August separated three cycles of growth of two months duration. Only 80% of the primaries and 50% of the secondaries became inactive in June, with 50% of the primaries and 30% of the secondaries, in August.

scholarly journals Direct actions of androgen, estrogen and anti-Müllerian hormone on primate secondary follicle development in the absence of FSH in vitro

2017 ◽  
Vol 32 (12) ◽  
pp. 2456-2464 ◽  
Author(s):  
T Baba ◽  
A Y Ting ◽  
O Tkachenko ◽  
J Xu ◽  
R L Stouffer
Keyword(s):  
Follicle Development ◽  
Secondary Follicle
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