Fig 1.
Determination of the lipid content and area and number of lymphatic aggregations in the liver.
(A) parietal surface of the liver of LD chickens with the sampling site boxed for light and transmission electron microscope. (B) lymphatic aggregation outlined in green. (C) cross section of liver stained with Haematoxylin and Eosin, where arrows are sinusoids. (D) lipid content determination using a colour thresholding filter: fat accumulations and sinusoids highlighted (green) areas. (E) unspecific selection of the sinusoids (arrows) was eliminated by using shape filter with circularity degree of ≥ 50%. Bar: 1 cm for A and 25 μm for B, C, D, E, light microscopy, H&E stained. (F) liver lipid droplets outlined in green. Bar: 1000 nm for F, transmission electron microscopy.
Table 1.
Histological analysis of the liver lipid content using shape filters compared to the lipid content derived from chemical analysis.
Fig 2.
Liver mass and normalised mass of both chicken lines.
Trendlines of the changes in mass (A) and normalised mass (B) of livers versus days post hatching for Ross and LD chicken lines. (C) linear regression line of logarithm of liver mass versus logarithm of total body weight for both chicken lines. Symbols represent each individual value for each chicken line. BW, body weight.
Fig 3.
Liver lipid content (%) estimated via histological method.
(A) Semi-thin section of a 1-day-old LD chick liver stained with Richardson blue. Where, (er) erythrocyte, (s) sinusoid, (asterisks) lipid droplets, (arrow) endothelial cell. Bar: 10 μm. (B) lipid liver content % versus age, bars refer to mean ± standard error of the mean of the sampled chicken at each time interval. (C) linear regression line of liver lipid content versus body weight. Symbols represent each individual value for each chicken line.
Table 2.
Area and number of the lymphatic aggregations in histological sections of LD and Ross chickens.
Table 3.
Percentage of lipid storage in the liver of LD and Ross chickens assessed by light microscopy.
Fig 4.
Transmission electron micrographs of the liver of 1 and 7 day old chicken of both lines.
(A and B) hepatocyte nuclei of 1-day-old Ross (A) and LD chicks (B). (C and D) concentrations of mitochondria in 7-day-old LD (C) and Ross chicks (D). (E) a panorama micrograph of hepatocytes and sinusoid of 7-day-old LD chicks. Where, (bc) bile canaliculus, (ec) endothelial cells, (er) erythrocyte, (m) mitochondria, (n) nucleus, (s) sinusoid lumen. (p) perisinusoidal space. Symbols: (arrow) mitochondria associated membranes. Bar 1000 μm.
Fig 5.
Transmission electron micrographs of the livers of both chicken lines.
(A) neighbouring hepatocytes in a 7-day-old LD chick, where the rough endoplasmic reticulum is arranged beneath the plasma membrane (broad arrows), mitochondria associated membranes (thin arrows). (B) glycogen accumulations in the liver of 14-day-old Ross chicks where (ly) lysosomes, (asterisk) glycogen accumulations. (C) hepatic stellate cell (Ito cell) (h) of a 1-day-old LD chick with a neighbouring (ec) endothelial cell. (D) erythrophagocytosis by Kupffer cells in a 1 day Ross chick where (er) erythrocyte, (k) nucleus of Kupffer cell, (arrowhead) pseudopod. Bar 1000 nm.
Table 4.
Lipid droplets percentage, number and diameter in the liver of LD and Ross chickens versus days post hatching under TEM.