Does the salivary fern pattern determine fertile period in reproductive female?

Mucin and salt combination simulate typical fern-like pattern of buffalo saliva smear at estrus

Estrus detection in buffaloes primarily relies on behavioral and physiological signs. Especially during summer, these signs are less prominent to recognize. Thus, estrus detection is a pronounced challenge within the realm of buffalo husbandry, particularly in the summer. Therefore, a simple and accurate estrus detection method is required for buffalo farmers. The observation of fern-like salivary crystallization patterns is one such simple method to detect estrus in buffaloes, bactrian camels, beagle bitches, and cows. However, the exact mechanism for the formation of typical fern-like is not known. We hypothesized that it might be because of the estrus-specific mucins and salts. To test this hypothesis, we prepared the smears by combining different concentrations of mucin type -2 (MUC2) and -3 (MUC3) with sodium chloride (NaCl). Microscopic examination confirmed that fern-like patterns resulted from a combination of the MUC3 and NaCl produced more realistic fern patterns than that of MUC2 or BSA with salt. To predict possible mucin and salt concentration showing natural fern-like patterns at the estrus stage in buffalo saliva, we constructed a guide tree of artificially generated fern-like patterns using an image analysis online tool. This computation analysis revealed that most of the natural buffalo estrus saliva samples showing typical fern-like patterns clustered in the cluster 2 of the guide tree comprising of 13 clusters. In the cluster 2, MUC3 in combination with the salt concentrations of 100, 150, and 250 mM was commonly found in a close proximity to the natural typical fern-like patterns of saliva smear of buffaloes at estrus. Conclusively, the buffalo saliva at estrus is predicted to have a gel-forming heavily glycosylated protein such as mucin along with at least 100 mM of NaCl. RESEARCH HIGHLIGHTS: Glycoprotein and salts combination replicates fern-like pattern of buffalo saliva at estrus. MUC3 and NaCl salt combination produces more realistic fern-like patterns compared with MUC2 or BSA and salt combination. MUC3 with NaCl at 100, 150, and 250 mM consistently resembled natural estrus saliva fern-like patterns. During estrus, buffalo saliva is expected to contain heavily glycosylated mucin and at least of 100 mM NaCl.

Shear-reversible clusters of HIV-1 in solution: stabilized by antibodies, dispersed by mucin

IMPORTANCE

The phenomenon of reversible clustering is expected to further nuance HIV immune stealth because virus surfaces can escape interaction with antibodies (Abs) by hiding temporarily within clusters. It is well known that mucin reduces HIV virulence, and the current perspective is that mucin aggregates HIV-1 to reduce infections. Our findings, however, suggest that mucin is dispersing HIV clusters. The study proposes a new paradigm for how HIV-1 may broadly evade Ab recognition with reversible clustering and why mucin effectively neutralizes HIV-1.

Validation of salivary ferning based estrus identification method in a large population of water buffaloes (Bubalus bubalis) using Foldscope

Missing an estrus event is an economic problem in buffaloes because of lack of a simple and accurate estrus identification method. Saliva, a non-invasive fluid available every time, showed typical fern-like crystallization patterns at early estrus in buffaloes. However, to implement this salivary ferning based estrus identification method in the field conditions, the present study, for the first time, validated this method in four buffalo population samples (PS) representing four different field scenarios, an organized herd (PS1, 10 buffaloes monitored daily for a year (149 estrus events)), artificial insemination (AI) centers (PS2, 114 buffaloes brought for AI), induced estrus condition (PS3, 44 buffaloes) and farmers' doorsteps (PS4, 275 random buffaloes with unknown reproductive history and no estrous signs). Totally, 582 saliva samples were collected from 443 buffaloes. Salivary smears were observed under a simple microscope and/or a less expensive (< 1USD) paper microscope, Foldscope. On the basis of salivary fern-like patterns, the proportions of estrus identification were significantly different among PS. Specifically, the proportions in the PS1 (0.74, P < 0.0001) and PS4 (0.08, P < 0.05) were significantly higher than their population proportion estimates, 0.5 and zero, respectively. Therefore, this estrus identification method is much useful in the PS1 and PS4, the practical field scenarios requiring an accurate estrus prediction method, compared to the PS2 and PS3. Especially, this method is 91 % confirmatory to detect early estrus in PS4. Therefore, salivary ferning is a useful technique to identify early estrus in buffaloes in the field conditions at farmers' doorsteps.