The use of overcorrection as a means to control drooling

The genome of the stable fly, Stomoxys calcitrans, reveals potential mechanisms underlying reproduction, host interactions, and novel targets for pest control

Background

The stable fly, Stomoxys calcitrans, is a major blood-feeding pest of livestock that has near worldwide distribution, causing an annual cost of over $2 billion for control and product loss in the USA alone. Control of these flies has been limited to increased sanitary management practices and insecticide application for suppressing larval stages. Few genetic and molecular resources are available to help in developing novel methods for controlling stable flies.

Results

This study examines stable fly biology by utilizing a combination of high-quality genome sequencing and RNA-Seq analyses targeting multiple developmental stages and tissues. In conjunction, 1600 genes were manually curated to characterize genetic features related to stable fly reproduction, vector host interactions, host-microbe dynamics, and putative targets for control. Most notable was characterization of genes associated with reproduction and identification of expanded gene families with functional associations to vision, chemosensation, immunity, and metabolic detoxification pathways.

Conclusions

The combined sequencing, assembly, and curation of the male stable fly genome followed by RNA-Seq and downstream analyses provide insights necessary to understand the biology of this important pest. These resources and new data will provide the groundwork for expanding the tools available to control stable fly infestations. The close relationship of Stomoxys to other blood-feeding (horn flies and Glossina) and non-blood-feeding flies (house flies, medflies, Drosophila) will facilitate understanding of the evolutionary processes associated with development of blood feeding among the Cyclorrhapha.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-00975-9.

Primary Metabolism co-Opted for Defensive Chemical Production in the Carabid Beetle, Harpalus pensylvanicus

Of the approximately one million described insect species, ground beetles (Coleoptera: Carabidae) have long captivated the attention of evolutionary biologists due to the diversity of defensive compounds they synthesize. Produced using defensive glands in the abdomen, ground beetle chemicals represent over 250 compounds including predator-deterring formic acid, which has evolved as a defensive strategy at least three times across Insecta. Despite being a widespread method of defense, formic acid biosynthesis is poorly understood in insects. Previous studies have suggested that the folate cycle of one-carbon (C1) metabolism, a pathway involved in nucleotide biosynthesis, may play a key role in defensive-grade formic acid production in ants. Here, we report on the defensive gland transcriptome of the formic acid-producing ground beetle Harpalus pensylvanicus. The full suite of genes involved in the folate cycle of C1 metabolism are significantly differentially expressed in the defensive glands of H. pensylvanicus when compared to gene expression profiles in the rest of the body. We also find support for two additional pathways potentially involved in the biosynthesis of defensive-grade formic acid, the kynurenine pathway and the methionine salvage cycle. Additionally, we have found an array of differentially expressed genes in the secretory lobes involved in the biosynthesis and transport of cofactors necessary for formic acid biosynthesis, as well as genes presumably involved in the detoxification of secondary metabolites including formic acid. We also provide insight into the evolution of the predominant gene family involved in the folate cycle (MTHFD) and suggest that high expression of folate cycle genes rather than gene duplication and/or neofunctionalization may be more important for defensive-grade formic acid biosynthesis in H. pensylvanicus. This provides the first evidence in Coleoptera and one of a few examples in Insecta of a primary metabolic process being co-opted for defensive chemical biosynthesis. Our results shed light on potential mechanisms of formic acid biosynthesis in the defensive glands of a ground beetle and provide a foundation for further studies into the evolution of formic acid-based chemical defense strategies in insects.

CoryneRegNet 7, the reference database and analysis platform for corynebacterial gene regulatory networks

We present the newest version of CoryneRegNet, the reference database for corynebacterial regulatory interactions, available at www.exbio.wzw.tum.de/coryneregnet/. The exponential growth of next-generation sequencing data in recent years has allowed a better understanding of bacterial molecular mechanisms. Transcriptional regulation is one of the most important mechanisms for bacterial adaptation and survival. These mechanisms may be understood via an organism's network of regulatory interactions. Although the Corynebacterium genus is important in medical, veterinary and biotechnological research, little is known concerning the transcriptional regulation of these bacteria. Here, we unravel transcriptional regulatory networks (TRNs) for 224 corynebacterial strains by utilizing genome-scale transfer of TRNs from four model organisms and assigning statistical significance values to all predicted regulations. As a result, the number of corynebacterial strains with TRNs increased twenty times and the back-end and front-end were reimplemented to support new features as well as future database growth. CoryneRegNet 7 is the largest TRN database for the Corynebacterium genus and aids in elucidating transcriptional mechanisms enabling adaptation, survival and infection.

Treatment Techniques to Encourage Lip Closure and Decrease Drooling in Persons with Cerebral Palsy

This study was designed to test the effectiveness of oral sensorimotor techniques in decreasing drooling. A withdrawal A1-B-A2 design was used with two subjects diagnosed as having mental retardation and cerebral palsy. The baseline phase consisted of 20-minute sessions of play, followed by a 45-minute period during which the subjects wore bibs The treatment phase was identical to the baseline phase except that the 20 minutes of play was replaced with 20 minutes of treatment. Treatment techniques included light touch to the midline of the lips, maintained pressure around the lips, stretch pressure, firm strokes applied on both sides of the larynx downward, and popsicle sucking. The amount of saliva collected on an absorbent bib during the 45-minute period that followed the 20 minutes was measured and recorded Although data sessions for one subject were marked by high session-to-session variability, the treatment effectively decreased drooling in both subjects.

Behavioral Treatment of Drooling

Many children with mental retardation and developmental disabilities suffer from the consequences of chronic drooling. Behavioral treatment for drooling should be considered before other, more intrusive treatments such as medication and surgery are implemented. However, empirical studies on behavioral procedures are scarce. This article reviews 19 behavioral studies published since 1970. Treatment procedures are (a) instruction, prompting, and positive reinforcement; (b) negative social reinforcement and declarative procedures; (c) cueing techniques; and (d) self-management procedures. Although these procedures yield positive results, critical examination of experimental methodology of the studies reveals several methodological shortcomings. Guidelines for clinical use of behavioral treatment for drooling are presented, and recommendations are given for future research in this area.

Overcorrection: Reviewed, revisited and revised

Overcorrection is a widely used behavior management procedure, the success of which has been well documented. However, overcorrection is not a simple, single procedure. Rather, it is a complex combination of procedures that often make it a complicated strategy to understand conceptually and to implement correctly. The complex nature of overcorrection combined with the use of multiple labels has created much confusion and debate among both researchers and practitioners. A number of issues relating to overcorrection are examined and evaluated. A proposal is made for revising the present overcorrection terminology. Finally, directions for future research are suggested.

A descriptive analysis of studies on behavioural treatment of drooling (1970-2005)

A descriptive analysis was conducted on studies on the behavioural treatment of drooling (published between 1970 and 2005). The 17 articles that met the inclusion criteria described 53 participants (mean age 14y 7mo, [SD 4y 9mo]; range 6-28y). Sex of 87% of the participants was reported: 28 male, 18 female. For 60% of the participants the degree of learning disability was reported, varying from severe/profound (n=24, 75%), moderate (n=4, 13%), to mild (n=2, 6%), while two participants (6%) had no learning disabilities. Forty-two participants (79%) were diagnosed with cerebral palsy. Behavioural procedures included instruction, positive and negative reinforcement, overcorrection and restitution, verbal and automatic cueing, and/or self-management. Effective behavioural procedures are reported in children with and without learning disability and/or motor impairment. Even participants with profound learning disability may benefit from behavioural intervention. However, the evidence base in terms of number of studies in this area is limited. Fifteen studies used a single participant design; two studies implemented an experimental-comparison group design. Some of these studies were poorly designed and methodological flaws were identified. Therefore, conclusions about efficacy of behaviour therapy for drooling and/or best practice cannot be drawn, although our analysis suggests that this approach is promising. However, future research on this topic is needed. After years of research focused on medical treatment, the option of behavioural treatment to reduce drooling should be reconsidered in relation to the medical management of this problem.

Management of drooling

Drooling is a frequent complaint for individuals with developmental disabilities and their families. A variety of treatment options exist including behavioral or oral motor therapies, medications and surgical interventions. Several novel alternative therapies are also being explored. However, most treatments lack evidence-based demonstration of efficacy. Management of problem drooling benefits from a team approach.

Nonsurgical treatment of drooling in a patient with closed head injury and severe dysarthria

The purpose of this investigation was to measure the effectiveness of the antimuscarinic drug atropine sulfate in the treatment of chronic drooling in a patient with a history of severe closed head injury and resultant widespread oral neuromuscular and higher cortical disturbances. Results of the A-B-A-B-A-B withdrawal paradigm, chosen to demonstrate the functional relationship between drug therapy and the degree of drooling, revealed that administration of atropine sulfate reduced by more than 50% of baseline levels the amount of resting secretion, intraoral accumulation, and pharyngeal-laryngeal pooling of saliva, with negligible side effects. These results are discussed and compared to the alternative drug and surgical approaches to treatment that have been the primary focus of recent research on drooling.