Predation and avoidance behaviour in aphid‐ladybird interactions of native and invasive ladybirds in Europe

1. While detrimental effects of invasive predators on native species are well documented, we often lack a mechanistic understanding of the invasion success. Lack of prey avoidance behaviour can lead to higher consumption rates by invasive predators compared to native predators. This competitive advantage is expected to contribute to the invasion success of non‐native predators.
2. We compared aphid consumption and cue avoidance behaviour of aphids between four native ladybird species (Coccinella septempunctata, Adalia bipunctata, Propylea quatuordecimpunctata, and Hippodamia variegata) and the invasive Asian ladybird Harmonia axyridis.
3. The invasive H. axyridis and the native C. septempunctata consumed more aphids than the three smaller native ladybird species. In line with our expectations, aphids avoided leaves bearing cues of most native ladybird species but not of the invasive H. axyridis.
4. Our results indicate that body size rather than ladybird origin determined aphid predation rates. The lack of aphid avoidance behaviour towards cues of H. axyridis indicates that they were not able to recognise the chemical cues of the invasive predator.
5. Relatively large body size and the absence of cue avoidance in aphids might benefit the invasive H. axyridis, particularly in comparison to smaller native ladybird species. The absence of avoidance behaviour in aphids might lead to even higher predation rates of H. axyridis under more natural conditions.

     

Amino terminal sequence of hog intrinsic factor.

1. Hog intrinsic factor has been purified from gastric mucosa by labile ligand affinity chromatography. 2. The following N-terminal amino acid sequence has been determined: Thr-Arg-Ser-Ser-Cys-Ser-Val-Pro-Ser-Ala-Glu-Gln-Pro-Leu-Val-Asn-Gly-Ile- Gln-Val - Leu-Met. 3. However, approx 60% of the preparation lacked the first two residues. 4. A high degree of homology between the amino terminal sequence of human and hog intrinsic factor exists.     

A second KRT71 allele in curly coated dogs

Major characteristics of coat variation in dogs can be explained by variants in only a few genes. Until now, only one missense variant in the KRT71 gene, p.Arg151Trp, has been reported to cause curly hair in dogs. However, this variant does not explain the curly coat in all breeds as the mutant ¹⁵¹Trp allele, for example, is absent in Curly Coated Retrievers. We sequenced the genome of a Curly Coated Retriever at 22× coverage and searched for variants in the KRT71 gene. Only one protein‐changing variant was present in a homozygous state in the Curly Coated Retriever and absent or present in a heterozygous state in 221 control dogs from different dog breeds. This variant, NM_001197029.1:c.1266_1273delinsACA, was an indel variant in exon 7 that caused a frameshift and an altered and probably extended C‐terminus of the KRT71 protein NP_001183958.1:p.(Ser422ArgfsTer?). Using Sanger sequencing, we found that the variant was fixed in a cohort of 125 Curly Coated Retrievers and segregating in five of 14 additionally tested breeds with a curly or wavy coat. KRT71 variants cause curly hair in humans, mice, rats, cats and dogs. Specific KRT71 variants were further shown to cause alopecia. Based on this knowledge from other species and the predicted molecular consequence of the newly identified canine KRT71 variant, it is a compelling candidate causing a second curly hair allele in dogs. It might cause a slightly different coat phenotype than the previously published p.Arg151Trp variant and could potentially be associated with follicular dysplasia in dogs.     

Histological and enzyme histochemical changes in the kidney of male bullhead (Cottus gobio) during the spawning period

Histological and enzyme histochemical studies were carried out on the excretory kidney of the male bullhead ( Cottus gobio ). During the spawning season striking morphofunctional changes were observed in the second proximal segment of the kidney tubule. The tubular epithelium was greatly hypertrophied, strongly basophilic and produced a PAS-positive secretion. The enzyme histochemical pattern also changed conspicuously during this time: the alkaline phosphatase activity in the brush border was greatly reduced; the acid phosphatase and non-specific esterase activity in the cytoplasm was distinctly elevated.