2013 Vol. 34, No. 1
Learned vocalizations (long call and song) of adult male songbirds start from the high vocal center (HVC), and are integrated and output by the robust nucleus of the arcopallium (RA), which connects synaptic relationships with the dorsomedial nucleus of the intercollicular complex (DM). To determine the effect on learned vocalization of the unilateral forebrain and midbrain in adult male zebra finch, electrolytic lesions and acoustic analysis technology were used. The results indicated that RA and DM nuclei are involved in the control of learned vocalization, and the right side is dominant in the forebrain and midbrain.
Here, we present our findings of free-flying echolocation calls of Himalayan swiftlets (Aerodramus brevirostris), which were recorded in Shenjing Cave, Hupingshan National Reserve, Shimen County, Hunan Province in June 2012, using Avisoft-UltraSoundGate 116(e). We noted that after foraging at dusk, the Himalayan swiftlets flew fast into the cave without clicks, and then slowed down in dark area in the cave, but with sounds. The echolocation sounds of Himalayan swiftlets are broadband, double noise burst clicks, separated by a short pause. The inter-pulse intervals between double clicks (99.3±3.86 ms)were longer than those within double clicks (6.6±0.42 ms) (P<0.01). With the exception of peak frequency, between 6.2±0.08 kHz and 6.2±0.10 kHz, (P>0.05) and pulse duration 2.9±0.12 ms, 3.2±0.17 ms, (P>0.05) between the first and second, other factors—maximum frequency, minimum frequency, frequency bandwidth, and power—were significantly different between the clicks. The maximum frequency of the first pulse (20.1±1.10 kHz) was higher than that of second (15.4±0.98 kHz) (P<0.01), while the minimum frequency of the first pulse (3.7±0.12 kHz) was lower than that of second (4.0±0.09 kHz) (P<0.05); resulting in the frequency bandwidth of the first pulse (16.5±1.17 kHz) longer than that of second (11.4±1.01 kHz) (P<0.01). The power of the first pulse (?32.5±0.60 dB) was higher than that of second (?35.2±0.94 dB) (P<0.05). More importantly, we found that Himalayan swiftlets emitted echolocation pulses including ultrasonic sound, with a maximum frequency reaching 33.2 kHz.
During breeding season in May, 2012, we recorded and analyzed the courtship calls and the acoustic parameters of the male Microhyla ornate in Lishui, Zhejiang province using an IC recorder (SX950) and the sound software Praat. We observed that the male M. ornate produced calls characterized by a single harmonic call structure, multiple pulses (7, 9?16) and spindle amplitudes. Analyses of the calls revealed several interesting findings: the dominant frequency of all calls ranged from 1.22?4.09 kHz (n=233); their average values composed of different numbers of pulses were similar and that call duration increased with numbers of pulses; and pulse duration among different multi-pulse call groups was nearly identical, but it was equal or less in the last pulse than other pulses. By contrast, our analyses also showed that pulse interval was negatively correlated with call duration, i.e. the shorter in call duration, the longer in pulse interval among the different numbers of pulses call groups. Within the 7-pulse call group, calls exhibited the largest in pulse interval and the smallest in pulse rate, while those calls in 16-pulse were the opposite. Except that the 7- and 16-pulse call groups were both significantly different in pulse rate with other multi-pulse call groups, we found that pulse rates expressed different variations between pair-wise comparisons of the remaining call groups. As for call intensity, significant differences were only found between the 16-pulse call group and the other call groups, while pairwise comparisons of the remaining groups were not significant. After conducting our initial analyses, we compared the calls of the M. ornate population from Lishui with populations from five other localities—Hangzhou, Xuancheng, Karnoor, Bajipe and Padil—and found that the call structures were similar among the different populations, being single harmonic, while we observed differences in call dominant frequency, call duration, pulse duration and pulse rate among the six populations. This research should prove useful to in furthering our understanding of the acoustic properties of species-specific calls as well as their behavior and the evolution of their communication, thereby providing a robust insight into the reproductive traits among different geographical populations of a species.
Correlations of two species of gamasid mites (Macronyssus pararadovskyi and M. radovskyi) and their bat hosts (Tylonycteris pachypus and T. robustula) were studied by field surveys and indoor behavioral experiments. The wild data indicated that mite load was positively correlated with body condition index of female T. pachypus hosts (Spearman: rs=0.55, P<0.01, n=24). Whereas, mite loads had no correlation with body condition indexes of male T. pachypus and all T. robustula hosts (P>0.05). Indoor original host infection showed that mites preferred male T. pachypus and T. robustula hosts. The infection percentages on male hosts were significantly higher than those on female hosts [T. pachypus: male (58±12)%, female (42±12)%, (t=?3.6, df=31, P<0.01); T. robustula: male (63±11)%, female (37±11)%, (t=?6.1, df=26, P<0.001)]. Using M. pararadovskyi (original host T. pachypus) to across infect T. pachypus and T. robustula, we found that mites significantly preferred the original host (t=9.1, df=29, P<0.001). The infection percentages of T. pachypus, and T. robustula were (71±13)% and (29±13)%, respectively. Our results indicated that mite loads of the two bat species were not correlated with body condition indexes of hosts. However, these mites presented different host sexual preferences, and the mites of T. pachypus presented specific host species preferences.
To investigate the potential protective effects of the snake venom antimicrobial peptide OH-CATH, we used a series of rabbit urinary tract infection models successfully induced by cephalosporin-resistant E.coli and E. coli ATCC 25922. The experimental models were administered saline, snake venom antimicrobial peptide OH-CATH, Cefoperazone and Sulbactam through the urethra. Urine was collected on days 1, 5, 10 and 14 after model establishment and urine culture was done to check the infection in each experimental animals. On day 14, all the animals were sacrificed and the bladder tissue specimens were taken for observation by H-E staining light microscope and transmission electron microscope. We found that the snake venom antimicrobial peptide OH-CATH reduced bacterial count in urine culture in both cephalosporin-resistant E. coli and the E. coli ATCC 25922 infected animals, while Cefoperazone and Sulbactam were only able to reduce the positive rate induced by the E. coli ATCC 25922 but had no obvious effects on animal model induced by cephalosporin-resistant E. coli strains (P<0.05). We also found less necrosis, degeneration and inflammatory cell infiltration in bladder tissue in OH-CATH groups as compared with the other experimental groups. The snake venom antimicrobial peptide OH-CATH had stable antibacterial activity against cephalosporin-resistant E. coli and E. coli ATCC 25922 and exhibited protective effects on both the cephalosporin-resistant E. coli and E. coli ATCC 25922 rabbit urinary tract infection models, suggesting that the molecule may have potential clinical applications in treating urinary tract infections.
Leukocyte cell-derived chemotaxin 2 (LECT2) is a secretory cytokine that functions in many physiological and pathological processes. We used a Pichia pastoris expression system for the recombinant expression of rainbow trout LECT2. The recombinant LECT2 was purified by UNOsphere S Cation exchange and size-exclusion chromatography columns. The obtained target protein was highly pure (>96% homogeneity) and the yield was >120 mg/L of yeast cultures. An in vitro chamber assay revealed that recombinant LECT2 could induce chemotactic responses in rainbow trout head kidney-derived macrophages. Recombinant LECT2 not only enhanced macrophage respiratory burst activity and bactericidal activity, but also changed macrophage gene expression. In summary, we established a rapid and efficient method to prepare active recombinant rainbow trout LECT2 using a yeast expression system and column chromatography. Bioactive recombinant LECT2 is essential for studies on protein functions.
Based on the EST sequence from a hemocyte cDNA library, the cathepsin L cDNA of Exopalaemon carinicauda (EcCatL) was cloned by rapid amplification of cDNA ends (RACE). The EcCatL cDNA was 1136 bp in length, which contains an open reading frame (ORF) of 960 bp, encoding a 319 amino-acid polypeptide. Homology analysis revealed that the amino acid sequence of EcCatL was highly conserved with its homologs in other crustaceans. The similarities of EcCatL with the CatL of Palaemonetes varians and Pandalus borealis were 92% and 76%, respectively. Phylogenetic analysis showed that EcCatL was in the same branch as that of Palaemonetes varians. The expression levels of EcCatL in different tissues were analyzed by quantitative real-time PCR. Expression of EcCatL was detected in all tested tissues of E. carinicauda, including hemocytes, gill, hepatopancreas, muscle, ovary, intestine, stomach and eyestalk, with the highest expression level in hepatopancreas. After challenged with Vibrio anguillarum or white spot syndrome virus, the expression of EcCatL were up-regulated in the hemocytes and hepatopancreas of E. carinicauda. Our results implied that EcCatL might play an important role in the prawn immune response.
Mating systems, as an evolutionary stable strategy, play an important role in animal reproductive process and result from an animal’s adaption to their environment, including their inter-specific environment. In the 1980s, extrapair paternity (EPP) was first noted in the eurychoric species, the Great Tit, Parus major. As earlier studies indicated, morphology, physiology, behavior, ecological characteristics and mating systems of eurychoric species differ greatly between areas or populations. Accordingly, we analyzed the mating system of the Great Tit (P.m.minor) in Fairy Cave National Nature Reserve, Liaoning, China. We collected total parent-offspring blood samples from 22 broods. We used 8 hypervariable loci, which were selected from 11 reported microsatellite loci for paternity test. In conjunction with the known genetic pattern of the female parent, the accuracy of the paternity testing reached 99.98% with this genetic data. Results of paternity testing showed that 7 of 22 broods (31.8%) had extra-pair nestling, with 16 of 197 nestlings (8.12%) a result of extra-pair fertilizations. The EPP rate of the Great Tit we noted in Liaoning is obviously lower than those in other passerine forest birds (less than 10%). Though between 55.6% and 9.1% extrapair offspring were found among the different nests, we were, however, unable to find any explanatory rule.
Several Black-crested Bulbul (Pycnonotus flaviventris) with red throats were observed and photographed in December 2010 and April 2011 in the Youjiang District (N23°54′, E06°36′, altitude 179 m) and Jingxi County(N22°59′, E1 06°40′, altitude 354 m) of Baise city, northwestern Guangxi, in southern China. These individuals belong to subspecies johnsoni, recorded previously in central and southeastern Thailand as well as the southern Indochina Region. This sighting provides a new record of the subspecies within China, warranting a discussion on the classification and distribution of Pycnonotus flaviventris.
In tandem with economic growth and rising living conditions, ecotourism has increasingly gained popularity among the Chinese public. Non-human primates, as charismatic animals and the closest relatives of human beings, have shown a strong affinity in attracting the general public and raising money, and for that reason a variety of monkey parks, valleys, and islands are becoming increasingly popular in China. Though successful in raising a substantial sum of money for the managing agency of a nature reserve, there may be negative impacts on monkey groups used in ecotourism. Here, to establish effective guards for non-human primates involved in ecotourism, we present a review on tourism disturbance and summarize the negative impacts on behavioral patterns, reproduction, and health condition of animals.