Genome-wide association studies for mottled eggs in chickens using a high-density single-nucleotide polymorphism array

Mottled eggs in layer chickens are gaining increasing attention because of the economic impact on the egg industry caused by the reduced sale value of commodity eggs. However, the genetic architecture underlying mottled eggs is not well understood. The genetic architecture underlying the mottled egg trait was investigated using genome-wide association studies (GWAS) by high-density arrays, using a total of 407 pink eggs and 799 blue eggs from an F₂ resource population generated by crossing Dongxiang Blue-shelled and White Leghorn chickens. The mottled egg score in blue eggs was found to be higher than that in pink eggs. The single-nucleotide polymorphism heritability of mottled egg at laying day and storage for 7 days was 0.18 and 0.20, respectively. Bivariate GWAS provided 29 significant loci, mainly located on GGA2, GGA3, GGA8, GGA10, GGA15, GGA17, and GGA23, affecting mottled egg on laying day. Candidate genes RIMS2, SLC25A32, RIMBP2, VPS13B, and RGS3 were obtained for mottled eggshell by bivariate GWAS and gene annotation. Our findings provide new insights into the genetic architecture of mottled egg in hens, and demonstrate that a genomic selection method would be profitable for breeding out the mottled egg trait.     

Low levels of organic compound trace elements improve the eggshell quality,antioxidant capacity,immune function,and mineral deposition of aged laying hens

In the egg production industry, trace elements are required as additional dietary supplements to play vital roles in performance and egg quality. Compared to inorganic microelements (ITs), appropriate dose of organic trace microelements (OTs) are environmentally friendly and sufficient to satisfy the needs of hens. In order to evaluate the extent to which low-dose OTs replace whole ITs, the effects of organic copper, zinc, manganese, and iron compound on the performance, eggshell quality, antioxidant capacity, immune function, and mineral deposition of old laying hens were investigated. A total of 1 080 57-week-old Jing Hong laying hens were assigned to five groups with six replicates of 36 layers each for an 8-week experimental period. The birds were fed either a basal diet (control treatment (CT)) or the basal diet supplemented with commercial levels of inorganic trace elements (IT 100%) or the equivalent organic trace elements at 20%, 30%, and 50% of the inorganic elements (OT 20%, OT 30%, and OT 50%, respectively). Results showed that compared with those in the CT treatment, feeding hens with inorganic or organic microelement diet had significant effects on the eggshell quality, antioxidant capacity, immune function, and mineral deposition of old laying hens (P < 0.05). The eggshell strength and ratio between OT 30%, OT 50%, and IT 100% were similar at weeks 4 and 8, and the eggshell thickness of these groups was also similar at weeks 6 and 8. At week 8, the eggshell colour in OT 50% was darker than that in IT 100%. The mineral content in the eggshells of OT 50% and IT 100% significantly increased (P < 0.001), with no significant difference in effective thickness, mammillary thickness, and mammillary knob width between groups. There were no differences in the malondialdehyde content, total antioxidant capacity, and total superoxide dismutase activity in serum between OT 30%, OT 50%, and IT100%. While the catalase activities, the interleukin-1β, interleukin-10, immunoglobulin G, and immunoglobulin M concentrations in serum were not significantly different between OT 50% and IT 100%. The mineral contents in the faeces of the organic groups were considerably reduced compared with those in IT 100% (P < 0.001). In conclusion, dietary supplementation with 30–50% organic compound microelements has the potential to replace 100% inorganic microelements in the hen industry for improving eggshell quality, mineral deposition in the eggshell, antioxidant capacity, and immune function, and reducing emissions to the environment without negative effects on laying performance.     

Interactive effects of vitamins A and K3 on laying performance,egg quality,tibia attributes and antioxidative status of aged Roman Pink laying hens

Extending laying cycle is a tendency in hen breeding, but egg quality declines as laying hens age. The present study was conducted to investigate the interactive effects of vitamins A and K₃ on laying performance, egg and tibia quality, and antioxidative status of aged Roman Pink laying hens. In a 3 × 3 factorial arrangement, 1 080 87-week-old laying hens were allocated to nine groups with eight replicates in each group. Deficient, adequate and excess vitamins A (0, 7 000 and 14 000 IU/kg) and K₃ (0, 2.0 and 4.0 mg/kg) were supplemented into a basal diet with 1 320 IU/kg of vitamin A and 0.5 mg/kg of vitamin K₃. After 2 weeks of adaption to basal diet, hens were fed corresponding diets for 8 weeks. Vitamins A and K₃ did not significantly affect the laying performance. However, they showed interactive effects on yolk ratio at week 93 as well as tibia weight and diameter (P < 0.05), and hens fed deficient vitamins A and K₃ had the highest yolk ratio and tibia weight, but the lowest tibia diameter. Compared with deficient addition, adequate or excess vitamins A and K₃ increased yolk color at weeks 93 and 97 (P < 0.05). Compared with hens fed deficient or excess vitamins, hens fed adequate vitamins A and K₃ had higher eggshell strength at week 93 or 97 (P < 0.05). Increasing vitamin A elevated plasma total superoxide dismutase (T-SOD) activity and decreased hepatic glutathione peroxidase (GSH-Px) activity (P < 0.05). Excess vitamin K₃ increased hepatic T-SOD activity (P < 0.05). Vitamins A and K₃ exhibited interaction on the activities of antioxidative enzymes in eggshell gland (P < 0.05), and adequate or excess vitamins A and K₃ increased the activities of GSH-Px, T-SOD and catalase (CAT). Adequate and excess vitamin A up-regulated the mRNA expression of GSH-Px1, GSH-Px3 and SOD1 in eggshell gland (P < 0.05). Vitamins A and K₃ showed interactive effects on CAT mRNA expression in eggshell gland (P < 0.05) and hens fed adequate vitamins A and K₃ had the highest CAT mRNA levels. In conclusion, dietary addition of vitamins A and K₃ improved the eggshell quality and yolk color as well as antioxidative status in eggshell gland of aged laying hens. Adequate vitamins A and K₃ showed beneficial effects and excess levels did not exhibit superior effects.     

An EAV-HP Insertion in 5′ Flanking Region of SLCO1B3 Causes Blue Eggshell in the Chicken

The genetic determination of eggshell coloration has not been determined in birds. Here we report that the blue eggshell is caused by an EAV-HP insertion that promotes the expression of SLCO1B3 gene in the uterus (shell gland) of the oviduct in chicken. In this study, the genetic map location of the blue eggshell gene was refined by linkage analysis in an F₂ chicken population, and four candidate genes within the refined interval were subsequently tested for their expression levels in the shell gland of the uterus from blue-shelled and non-blue-shelled hens. SLCO1B3 gene was found to be the only one expressed in the uterus of blue-shelled hens but not in that of non-blue-shelled hens. Results from a pyrosequencing analysis showed that only the allele of SLCO1B3 from blue-shelled chickens was expressed in the uterus of heterozygous hens (O*LC/O*N). SLCO1B3 gene belongs to the organic anion transporting polypeptide (OATP) family; and the OATPs, functioning as membrane transporters, have been reported for the transportation of amphipathic organic compounds, including bile salt in mammals. We subsequently resequenced the whole genomic region of SLCO1B3 and discovered an EAV-HP insertion in the 5′ flanking region of SLCO1B3. The EAV-HP insertion was found closely associated with blue eggshell phenotype following complete Mendelian segregation. In situ hybridization also demonstrated that the blue eggshell is associated with ectopic expression of SLCO1B3 in shell glands of uterus. Our finding strongly suggests that the EAV-HP insertion is the causative mutation for the blue eggshell phenotype. The insertion was also found in another Chinese blue-shelled breed and an American blue-shelled breed. In addition, we found that the insertion site in the blue-shelled chickens from Araucana is different from that in Chinese breeds, which implied independent integration events in the blue-shelled chickens from the two continents, providing a parallel evolutionary example at the molecular level.     

Dietary supplementation with sodium bicarbonate or sodium sulfate affects eggshell quality by altering ultrastructure and components in laying hens

Dietary sodium (Na) levels were related to the content of the eggshell matrix. We therefore speculated that dietary Na supplementation as sodium bicarbonate (NaHCO₃) or sodium sulfate (Na₂SO₄) may improve eggshell quality. Additionally, dietary NaHCO₃ or Na₂SO₄ supplementation may further affect eggshell quality in different ways due to differences in anions. This study investigated and compared the effects of dietary Na supplementation in either NaHCO₃ or Na₂SO₄ form on laying performance, eggshell quality, ultrastructure and components in laying hens. A total of 576 29-week-old Hy-Line Brown laying hens were randomly allocated to 8 dietary treatments that were fed a Na-deficient basal diet (0.07% Na, 0.15% Cl) supplemented with Na₂SO₄ or NaHCO₃ at 0.08, 0.18, 0.23 or 0.33% Na for 12 weeks. No differences were observed in laying production performance with dietary Na supplementation. Dietary Na supplementation resulted in quadratic increases of eggshell breaking strength in both Na₂SO₄ and NaHCO₃ added groups (P < 0.05), and Na₂SO₄-fed groups had a quadratic increase in the eggshell ratio at week 12 (P < 0.05). Compared with supplementing 0.08% Na, dietary supplementation of 0.23% Na increased the effective thickness (P < 0.05) in both Na₂SO₄ and NaHCO₃ added groups, but decreased the thickness and knob width of the mammillary layer (P < 0.05). A linear increase on the calcium content of the shell was only observed with Na supplementation from NaHCO₃ (P < 0.05). No differences were observed in Na contents of the shell with dietary Na supplemented by both sources. Dietary Na addition had a quadratic increase on uronic acid contents of shell membrane in NaHCO₃-fed groups (P < 0.05). Moreover, the sulfated glycosaminoglycan (GAG) contents of shell membranes increased linearly with dietary Na supplementation (P < 0.05). Dietary supplementation of 0.23% Na from Na₂SO₄ increased the sulfated GAG contents of calcified eggshell (P < 0.05). Additionally, compared with NaHCO₃-fed groups, Na₂SO₄-fed groups had higher eggshell breaking strength, thickness, eggshell weight ratio, effective thickness and the sulfated GAG contents of calcified eggshell at week 12. Overall, dietary supplementation of NaHCO₃ or Na₂SO₄ could increase eggshell breaking strength, which may be related to increased sulfated GAG contents in eggshell membranes and improved ultrastructure. Higher eggshell breaking strength, thickness and eggshell ratio could be obtained when the diet was supplemented with 0.23% Na from Na₂SO₄.     

The structure of the egg-shell of gLobodera rostochiensis (Nematoda: Tylenchida)

Perry R. N., Wharton D. A. and Clarke A. J. 1982. The structure of the egg-shell of Globodera rostochiensis (Nematoda: Tyienchida). International Journal for Parasitology12: 481–485. The ultrastructure and histochemistry of the egg-shell of Globodera rostochiensis are described. The eggshell consists of an outer vitelline layer, a chitinous layer and an inner lipid layer. The vitelline layer is not unit membrane-like and has strands of particulate material attached to its outer surface. The chitinous layer is made up of fibres consisting of a chitin microfibril core, surrounded by a protein coat. The lipid layer contains lipoprotein membranes. These vary in number, the most commonly observed pattern being two or three membranes loosely associated with the inner surface of the egg-shell.     

Effects of methyl mercury at different dose regimes on eggshell formation and some biochemical characteristics of the eggshell gland mucosa of the domestic fowl

Eggshell formation and egg production in domestic fowl were studied following the administration of methyl mercury (two dose regimes: 5 mg daily for 6 consecutive days and 1 mg daily for 50 consecutive days). A daily oral dose of 5 mg of methyl mercury for 6 consecutive days induced significant eggshell thinning and deformation and inhibited egg production. Uptake of ⁴⁵Ca and synthesis of prostaglandins by a homogenate of eggshell gland mucosa from methyl-mercury-treated birds were significantly reduced, as was the calcium content of blood plasma. A daily oral dose of 1 mg of methyl mercury administered for 50 consecutive days also induced eggshell deformation and thinning and reduced egg production. This dose did not, however, have significant effects on the following: ⁴⁵Ca uptake and prostaglandin synthesis by a homogenate of the eggshell gland mucosa; ⁴⁵Ca uptake by a homogenate of duodenal mucosa; the Ca content of the blood plasma, shell gland mucosa or shell gland lumen; the HCO₃⁻ content of the shell gland lumen or the specific gravity of tibia. Methyl mercury added in vitro to a homogenate of eggshell gland mucosa significantly stimulated the synthesis of prostaglandins PGF_2α and PGE₂. Addition of mercury chloride to the same type of preparation stimulated the synthesis of PGF_2α at the expense of thromboxane (T × B₂) synthesis. Administration of 5 mg methyl mercury for 6 consecutive days seemed to reduce the availability of calcium for eggshell formation. This effect could have been due to a direct inhibitory effect of methyl mercury on calcium uptake from the gastrointestinal tract and/or to mobilization of medullary bone. The administration of 1 mg methyl mercury for 50 consecutive days probably induced the reproductive effects by another mechanism. The effects of methyl mercury on avian eggshell formation are quite different from the effects p,p′-DDE exerts on that process.     

The eggshell structure in apteryx; form,function, and adaptation

Apteryx is a genus of flightless birds endemic to New Zealand known to lay very large eggs in proportion to body weight. The eggshell of Apteryx is unusually thin and less porous than allometrically expected possibly as a compensation for a very long incubation period. Past studies have been carried out on Apteryx australis, a species which once comprised all kiwi with brown plumage, now separated into three distinct species. These species use different habitats and live at different latitudes and altitudes, therefore generating a need to revise our knowledge of the attributes of their eggshells. In this study, we measured the physical characteristics and water conductance on eggshell fragments of these three species and Great‐spotted Kiwi and relate them to the environmental conditions of their respective environments; we also measured the water vapor conductance of Brown Kiwi eggs of late stages of incubation. We found that several trade‐offs exist between incubation behavior, environmental conditions, and eggshell structure. We found differences between species in eggshell water vapor conductance seemingly related to altitude; Brown Kiwi and Rowi generally inhabiting lower altitudes had the highest conductance and Tokoeka, generally living in montane environments, the lowest. This is achieved by an increased eggshell thickness rather than a pore area reduction. Finally, the water vapor conductance late in incubation was 58% higher than infertile unincubated eggs, suggesting a drastic increase in conductance throughout the long incubation period. Using the values previously reported, we calculated the embryonic eggshell thinning to be 32.5% at the equatorial region of the eggshell. We describe several new features, such as triangular mineral particles in the cuticle, reported for the extinct Trigonoolithus amoei, and confirmed the existence of plugged pores. We suggest that these structures provide microbial protection needed by a burrow nesting species with a long incubation period.     

Genome-wide association mapping and agronomic impact of cowpea root architecture

Key message

Genetic analysis of data produced by novel root phenotyping tools was used to establish relationships between cowpea root traits and performance indicators as well between root traits and Striga tolerance.

Abstract

Selection and breeding for better root phenotypes can improve acquisition of soil resources and hence crop production in marginal environments. We hypothesized that biologically relevant variation is measurable in cowpea root architecture. This study implemented manual phenotyping (shovelomics) and automated image phenotyping (DIRT) on a 189-entry diversity panel of cowpea to reveal biologically important variation and genome regions affecting root architecture phenes. Significant variation in root phenes was found and relatively high heritabilities were detected for root traits assessed manually (0.4 for nodulation and 0.8 for number of larger laterals) as well as repeatability traits phenotyped via DIRT (0.5 for a measure of root width and 0.3 for a measure of root tips). Genome-wide association study identified 11 significant quantitative trait loci (QTL) from manually scored root architecture traits and 21 QTL from root architecture traits phenotyped by DIRT image analysis. Subsequent comparisons of results from this root study with other field studies revealed QTL co-localizations between root traits and performance indicators including seed weight per plant, pod number, and Striga (Striga gesnerioides) tolerance. The data suggest selection for root phenotypes could be employed by breeding programs to improve production in multiple constraint environments.

     

Assignment of configuration at quaternary centres in pairs of 3-C Hydroxymethyl and 3-C methyl branched chain 1,2:4,6-diacetalated aldohexopyranose derivatives using 13C-N.M.R. spectoscopy

The configuration at the C-3 quaternary carbon atoms in two pairs (1 and 2, 3 and 4) of 3-C-hydroxymethyl, branched-chain, 1,2:4,6-diacetalated aldohexo-pyranoses have been determined from their ¹³ C-n.m.r. spectra. The stereochemical assignments were achieved by comparison of the spectra with those of the Z (13) and E isomers (14) of 4-tert-butyl-l-hydroxymethylcyclohexanol and with those of the corresponding diacetalated gluco- and allo-pyranoses (5, 6, 9, and 10). The spectra of 13 and 14 showed that an axial hydroxyl group shielded the α, β, and μ ring carbon atoms more than an axial hydroxymethyl group and that the carbon atom in the latter group was shielded relative to that in an equatorial hydroxymethyl group The spectra of 5, 6, 9, and 10 indicated the effect of an axial HO-3 on the shifts of the carbon atoms in the 1,2-O-alkylidene groups. The stereochemistry of an isomeric pair of 1,2:4,6-di-O-alkylidene-3-C-methyl-aldohexopyranoses (11 and 12) has also been determined.     

Effects of Increasing Supplementation of Magnesium in Diets on Productive Performance and Eggshell Quality of Aged Laying Hens

Magnesium (Mg) concentrations in diets have been associated with performance and eggshell quality of laying hens, but the results have been inconclusive. In this experiment, the effects of increasing concentrations of dietary Mg on productive performance and eggshell quality of aged laying hens were evaluated. A total of 640 Hy-Line Brown laying hens of 72 weeks of age were randomly allotted to one of four dietary treatments with four replicates per treatment. A commercial-type basal diet containing 1.6 g/kg Mg was prepared, and three additional diets were prepared to contain 2.3, 2.6, or 3.0 g/kg Mg in diets by adding 1.0, 1.5, or 2.0 g of MgO to the basal diet. The diets were fed to hens ad libitum for 5 weeks. Results indicated that Mg concentrations in eggshells were increased (linear, P?<?0.01) with increasing concentrations of Mg in diets. Increasing concentrations of Mg in diets decreased (linear and quadratic, P?<?0.01) broken and shell-less egg production, but improved (linear, P?<?0.05) eggshell strength. Feed intake was decreased (linear, P?<?0.05) with the concentrations of Mg in diets, but hen-day egg production, egg weight, feed conversion ratio, and Haugh unit were not affected by increasing concentrations of Mg in diets. Hunter L* and a* values of eggshell were decreased (linear, P?<?0.05) as the concentrations of Mg in diets increased. In conclusion, feeding aged laying hens with diets containing increasing concentrations of Mg up to 3.0 g/kg improves eggshell strength, but has no detrimental effects on laying performance.     

Inhibition of prostaglandin synthesis in eggshell gland mucosa as a mechanism for P,P'-DDE-induced eggshell thinning in birds—a comparison of ducks and domestic fowls

1. A recent report from the present laboratory indicated that the DDT-metabolite p,p'-DDE, which produces eggshell thinning in sensitive species of birds, inhibits prostaglandin synthesis in the eggshell gland.2. This was found to be true both after in vitro addition to a homogenate of eggshell gland mucosa from ducks, and after in vivo administration to ducks at a dose regimen that produces eggshell thinning.3. The purpose of the present study was to compare the p,p'-DDE-sensitive duck and the insensitive domestic fowl regarding the effects of p,p'-DDE administration on calcium and prostaglandin metabolism of the eggshell gland mucosa.4. Administration of p,p'-DDE caused significant eggshell thinning in ducks (−18.5%) but not in the domestic fowl.5. The shell thinning in ducks was accompanied by significant reductions in ⁴⁵Ca uptake and prostaglandin synthesis by a homogenate of the eggshell gland mucosa, as well as significant reductions of the prostaglandin E₂ content in the shell gland and the content of calcium and bicarbonate present in the shell gland lumen at the time of slaughter; the content of calcium in the eggshell gland mucosa was significantly increased.6. None of the changes was observed in the domestic fowl.7. Based on these findings, inhibition of a prostaglandin-stimulated bicarbonate transport across the eggshell gland mucosa is discussed as a possible mechanism for p,p '-DDE-induced eggshell thinning in birds.     

Design,synthesis and antibacterial activities of thiouracil derivatives containing acyl thiourea as SecA inhibitors

A series of novel thiouracil derivatives containing an acyl thiourea moiety (7a–7x) have been synthesized by structural modification of a lead SecA inhibitor, 2. All the compounds have been evaluated for their antibacterial activities against Bacillus amyloliquefaciens, Staphylococcus aureus, and Bacillus subtilis. Compounds 7c, 7m, 7u, 7v exhibited promising activities against above bacteria. Such four compounds were further tested for their inhibitory activity against SecA ATPase, and the results showed that compounds 7c and 7u had higher inhibitory activities than that of compound 2. Molecular docking work suggests that compound 7u might bind at a pocket close to the ATPase ATP-binding domain.     

Polymorphisms in Ion Transport Genes Are Associated with Eggshell Mechanical Property

Eggshell mechanical property traits such as eggshell breaking strength (ESS), eggshell thickness (EST) and eggshell weight (ESW) are most common and important indexes to evaluate eggshell quality in poultry industry. Uterine ion transporters involve in eggshell formation and might be associated with eggshell mechanical property traits. In this study, 99 SNPs in 15 ion transport genes were selected to genotype 976 pedigreed hens of Rhode Island Red. ESS, EST and ESW were measured for each bird at 55 weeks of age. The association study showed that 14 SNPs in 8 genes were significantly related (p < 0.05) with at least one trait, and their contributions to phenotypic variance ranged from 0.23% to 4.14%. Both ATP2A3 and SLC4A5 had a significant effect on all the three traits. Strong linkage disequilibrium (LD) was detected among SNPs in four genes: ATP2A3, ITPR1, SLC8A3, SCNN1a. The significant effects of those diplotypes on eggshell mechanical property traits were found, and their contributions to phenotypic variance ranged from 0.50% to 0.70%. It was concluded that the identified SNPs and diplotypes in this study were potential markers influencing the eggshell mechanical properties, which could contribute to the genetic improvement of eggshell quality.     

Ultrastructure of the protonephridial system of Polystomoides malayi Rohde and P. renschi Rohde (Monogenea: Polystomatidae)

Rohde K. 1973. Ultrastructure of the protonephridial system of Polystomoides malayi Rohde and P. renschi Rohde (Monogenea : Polystomatidae). International Journal for Parasitology3: 329–333. Polystomoides malayi and P. renschi have three types of protonephridial flames. The first type is a typical flame cell with internal and external ribs connected by a weir membrane without nephrostomes, and with internal and external leptotriches. The second type is a flame cell complex consisting of at least two flames reaching into a common cavity. The third type is a non-terminal (= lateral) flame in the protonephridial ducts, consisting of loosely arranged cilia many of which have lateral tube-like extensions and whose tips have irregularly arranged filaments gradually decreasing in number. The number of cilia in all types of flames varies. The smallest capillaries are strongly convoluted and have a smooth or slightly reticulated surface, the larger ducts have strongly reticulated walls and single cilia may be found in the cavities of the reticulum.     

Rhodium-diphosphite catalysed hydroformylation of allylbenzene and propenylbenzene derivatives

The asymmetric hydroformylation of allylbenzenes and propenylbenzenes is an important tool for obtaining high value intermediates for the pharmaceutical and perfume industry. We have studied these reactions with rhodium-chiral diphosphite systems. The diphosphite ligands 6 and 7 with carbohydrate backbone have high regioselectivities in trans-anethole hydroformylation and moderate ones in estragole hydroformylation. Only low enantioselectivities have been observed in the trans-anethole hydroformylation with the diphosphite 6 based system.     

Genome Size Evolution Mediated by Gypsy Retrotransposons in Brassicaceae

The dynamic activity of transposable elements (TEs) contributes to the vast diversity of genome size and architecture among plants. Here, we examined the genomic distribution and transposition activity of long terminal repeat retrotransposons (LTR-RTs) in Arabidopsis thaliana (Ath) and three of its relatives, Arabidopsis lyrata (Aly), Eutrema salsugineum (Esa), and Schrenkiella parvula (Spa), in Brassicaceae. Our analyses revealed the distinct evolutionary dynamics of Gypsy retrotransposons, which reflects the different patterns of genome size changes of the four species over the past million years. The rate of Gypsy transposition in Aly is approximately five times more rapid than that of Ath and Esa, suggesting an expanding Aly genome. Gypsy insertions in Esa are strictly confined to pericentromeric heterochromatin and associated with dramatic centromere expansion. In contrast, Gypsy insertions in Spa have been largely suppressed over the last million years, likely as a result of a combination of an inherent molecular mechanism of preferential DNA removal and purifying selection at Gypsy elements. Additionally, species-specific clades of Gypsy elements shaped the distinct genome architectures of Aly and Esa.     

Metabolites of Cercospora. Taiwapyrone,an α-pyrone of unusual structure from Cercospora taiwanensis

(+)-Mellein (1), cis-3S,4S-4-hydroxymellein (3), and taiwapyrone (4), a new α-pyrone, have been isolated from the mycelium of Cercospora taiwanensis, grown on potato-agar. The structure and absolute configuration of (3) and (4) have been elucidated.     

Eremophilane-type glucosides from the leaves of Ligularia calthifolia Maxim

Three eremophilane-type glucosides (1–3) along with three known congeners alticolosides A, B and D (4–6) have been isolated from the leaves of Ligularia calthifolia Maxim. (Asteraceae). The structures of 1–3 have been elucidated by spectroscopic analysis as well as by chemical transformations. A distinctive feature of the compounds 1–3 is the presence of an acetyl group in the glucose residues. The compounds were non-cytotoxic against human normal prostate cells as well as prostate cancer cells.     

The effect of developmental stage on eggshell thickness variation in endangered falcons

We compared eggshell thickness of hatched eggs with that of non-developed eggs in endangered falcon taxa to explore the effect of embryo development on eggshell thinning. To our knowledge, this has never been examined before in falcons, despite the fact that eggshell thinning due to pollutants and environmental contamination is often considered the most common cause of egg failure in falcons. Because of the endangered nature of these birds, and the difficulty in gaining access to the nests and their eggs, there is a large gap in our knowledge regarding eggshell thickness variation and the factors affecting it. We used a linear mixed-effects (LME) model to explore the variation in eggshell thickness (n = 335 eggs) in relation to the developmental stage of the eggs, but also in relation to the falcon taxa, the laying sequence and the study zone. Female identity (n = 69) and clutch identity (n = 98) were also included in the LME model. Our results are consistent with the prediction that eggshell thickness decreases during incubation because of the important effect of calcium uptake by the embryo during development. Our results also show that eggs laid later in the sequence had significantly thinner eggshells. In this study, we provide the first quantitative data on eggshell thickness variation of hatched eggs in different falcon taxa that were not subjected to contamination or food limitation (i.e., bred under captive conditions). Because eggshell thickness strongly influences survival and because the species examined in this study are endangered, our data represent a valuable control for future studies on the effects of pollution on eggshells from wild populations and thus are an important contribution to the conservation of falcons.